Introduction
Test Result
Result ID | Profile | Start time | End time | Benchmark | Benchmark version |
xccdf_org.open-scap_testresult_usgcb-rhel6-server | usgcb-rhel6-server | 2014-10-07 12:12 | 2014-10-07 12:28 | embedded | 0.9 |
Target info
Targets
|
Addresses
|
Applicable platforms
|
Score
system | score | max | % | bar |
urn:xccdf:scoring:default | 63.09 | 100.00 | 63.09% |
Results overview
Rule Results Summary
pass | fixed | fail | error | not selected | not checked | not applicable | informational | unknown | total |
90 | 47 | 59 | 20 | 176 | 4 | 0 | 0 | 3 | 399 |
Rule results summary
Results details
Result for Ensure /tmp Located On Separate Partition
Result: fail
Rule ID: partition_for_tmp
Time: 2014-10-07 12:13
Severity: low
The /tmp
directory is a world-writable directory used
for temporary file storage. Ensure it has its own partition or
logical volume at installation time, or migrate it using LVM.
The /tmp
partition is used as temporary storage by many programs.
Placing /tmp
in its own partition enables the setting of more
restrictive mount options, which can help protect programs which use it.
Security identifiers
- CCE-26435-8
Result for Ensure /var Located On Separate Partition
Result: fail
Rule ID: partition_for_var
Time: 2014-10-07 12:13
Severity: low
The /var
directory is used by daemons and other system
services to store frequently-changing data. Ensure that /var
has its own partition
or logical volume at installation time, or migrate it using LVM.
Ensuring that /var
is mounted on its own partition enables the
setting of more restrictive mount options. This helps protect
system services such as daemons or other programs which use it.
It is not uncommon for the /var
directory to contain
world-writable directories installed by other software packages.
Security identifiers
- CCE-26639-5
Result for Ensure /var/log Located On Separate Partition
Result: fail
Rule ID: partition_for_var_log
Time: 2014-10-07 12:13
Severity: low
System logs are stored in the /var/log
directory.
Ensure that it has its own partition or logical
volume at installation time, or migrate it using LVM.
Placing /var/log
in its own partition
enables better separation between log files
and other files in /var/
.
Security identifiers
- CCE-26215-4
Result for Ensure /var/log/audit Located On Separate Partition
Result: fail
Rule ID: partition_for_var_log_audit
Time: 2014-10-07 12:13
Severity: low
Audit logs are stored in the /var/log/audit
directory. Ensure that it
has its own partition or logical volume at installation time, or migrate it
later using LVM. Make absolutely certain that it is large enough to store all
audit logs that will be created by the auditing daemon.
Placing /var/log/audit
in its own partition
enables better separation between audit files
and other files, and helps ensure that
auditing cannot be halted due to the partition running out
of space.
Security identifiers
- CCE-26436-6
Result for Ensure /home Located On Separate Partition
Result: fail
Rule ID: partition_for_home
Time: 2014-10-07 12:13
Severity: low
If user home directories will be stored locally, create a separate partition
for /home
at installation time (or migrate it later using LVM). If
/home
will be mounted from another system such as an NFS server, then
creating a separate partition is not necessary at installation time, and the
mountpoint can instead be configured later.
Ensuring that /home
is mounted on its own partition enables the
setting of more restrictive mount options, and also helps ensure that
users cannot trivially fill partitions used for log or audit data storage.
Security identifiers
- CCE-26557-9
Result for Ensure Red Hat GPG Key Installed
Result: pass
Rule ID: ensure_redhat_gpgkey_installed
Time: 2014-10-07 12:13
Severity: high
To ensure the system can cryptographically verify base software packages come from Red Hat (and to connect to the Red Hat Network to receive them), the Red Hat GPG key must properly be installed. To install the Red Hat GPG key, run:
$ sudo rhn_register
If the system is not connected to the Internet or an RHN Satellite,
then install the Red Hat GPG key from trusted media such as
the Red Hat installation CD-ROM or DVD. Assuming the disc is mounted
in /media/cdrom
, use the following command as the root user to import
it into the keyring:
$ sudo rpm --import /media/cdrom/RPM-GPG-KEY
The Red Hat GPG key is necessary to cryptographically verify packages are from Red Hat.
Security identifiers
- CCE-26506-6
Result for Ensure gpgcheck Enabled In Main Yum Configuration
Result: pass
Rule ID: ensure_gpgcheck_globally_activated
Time: 2014-10-07 12:13
Severity: high
The gpgcheck
option controls whether
RPM packages' signatures are always checked prior to installation.
To configure yum to check package signatures before installing
them, ensure the following line appears in /etc/yum.conf
in
the [main]
section:
gpgcheck=1
Ensuring the validity of packages' cryptographic signatures prior to installation ensures the authenticity of the software and protects against malicious tampering.
Security identifiers
- CCE-26709-6
Result for Ensure gpgcheck Enabled For All Yum Package Repositories
Result: pass
Rule ID: ensure_gpgcheck_never_disabled
Time: 2014-10-07 12:13
Severity: high
To ensure signature checking is not disabled for
any repos, remove any lines from files in /etc/yum.repos.d
of the form:
gpgcheck=0
Ensuring all packages' cryptographic signatures are valid prior to installation ensures the authenticity of the software and protects against malicious tampering.
Security identifiers
- CCE-26647-8
Result for Ensure Software Patches Installed
Result: notchecked
Rule ID: security_patches_up_to_date
Time: 2014-10-07 12:13
Severity: high
If the system is joined to the Red Hat Network, a Red Hat Satellite Server, or a yum server, run the following command to install updates:
$ sudo yum update
If the system is not configured to use one of these sources, updates (in the form of RPM packages)
can be manually downloaded from the Red Hat Network and installed using rpm
.
Installing software updates is a fundamental mitigation against the exploitation of publicly-known vulnerabilities.
Security identifiers
- CCE-27635-2
Result for Install AIDE
Result: fixed
Rule ID: package_aide_installed
Time: 2014-10-07 12:28
Severity: medium
Install the AIDE package with the command:
$ sudo yum install aide
The AIDE package must be installed if it is to be available for integrity checking.
Security identifiers
- CCE-27024-9
Remediation script
yum -y install aide
Result for Verify and Correct File Permissions with RPM
Result: fail
Rule ID: rpm_verify_permissions
Time: 2014-10-07 12:17
Severity: low
The RPM package management system can check file access permissions of installed software packages, including many that are important to system security. After locating a file with incorrect permissions, run the following command to determine which package owns it:
$ rpm -qf FILENAME
Next, run the following command to reset its permissions to
the correct values:
$ sudo rpm --setperms PACKAGENAME
Permissions on system binaries and configuration files that are too generous could allow an unauthorized user to gain privileges that they should not have. The permissions set by the vendor should be maintained. Any deviations from this baseline should be investigated.
Security identifiers
- CCE-26731-0
group ownership of all files matches local rpm database
name | epoch | version | release | arch | filepath | extended name | size differs | mode differs | md5 differs | device differs | link mismatch | ownership differs | group differs | mtime differs | capabilities differ | configuration file | documentation file | ghost file | license file | readme file |
gdm | 1 | 2.30.4 | 52.el6 | i686 | /var/log/gdm | gdm-1:2.30.4-52.el6.i686 | pass | fail | not performed | pass | pass | pass | fail | pass | pass | false | false | false | false | false |
mode of all files matches local rpm database
name | epoch | version | release | arch | filepath | extended name | size differs | mode differs | md5 differs | device differs | link mismatch | ownership differs | group differs | mtime differs | capabilities differ | configuration file | documentation file | ghost file | license file | readme file |
ca-certificates | (none) | 2013.1.94 | 65.0.el6 | noarch | /etc/pki/ca-trust/extracted/openssl/ca-bundle.trust.crt | ca-certificates-0:2013.1.94-65.0.el6.noarch | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
ca-certificates | (none) | 2013.1.94 | 65.0.el6 | noarch | /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem | ca-certificates-0:2013.1.94-65.0.el6.noarch | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
ca-certificates | (none) | 2013.1.94 | 65.0.el6 | noarch | /etc/pki/ca-trust/extracted/pem/objsign-ca-bundle.pem | ca-certificates-0:2013.1.94-65.0.el6.noarch | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
rhn-client-tools | (none) | 1.0.0.1 | 16.el6 | noarch | /etc/sysconfig/rhn/up2date | rhn-client-tools-0:1.0.0.1-16.el6.noarch | fail | fail | not performed | pass | pass | pass | pass | fail | pass | true | false | false | false | false |
system-config-firewall-base | (none) | 1.2.27 | 5.el6 | noarch | /etc/sysconfig/system-config-firewall | system-config-firewall-base-0:1.2.27-5.el6.noarch | pass | fail | not performed | pass | pass | pass | pass | pass | pass | true | false | true | false | false |
ca-certificates | (none) | 2013.1.94 | 65.0.el6 | noarch | /etc/pki/ca-trust/extracted/pem/email-ca-bundle.pem | ca-certificates-0:2013.1.94-65.0.el6.noarch | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
PackageKit | (none) | 0.5.8 | 21.el6 | i686 | /var/lib/PackageKit/transactions.db | PackageKit-0:0.5.8-21.el6.i686 | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
ca-certificates | (none) | 2013.1.94 | 65.0.el6 | noarch | /etc/pki/ca-trust/extracted/java/cacerts | ca-certificates-0:2013.1.94-65.0.el6.noarch | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
kernel | (none) | 2.6.32 | 431.el6 | i686 | /boot/initramfs-2.6.32-431.el6.i686.img | kernel-0:2.6.32-431.el6.i686 | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
cronie-anacron | (none) | 1.4.4 | 12.el6 | i686 | /var/spool/anacron/cron.monthly | cronie-anacron-0:1.4.4-12.el6.i686 | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
cronie-anacron | (none) | 1.4.4 | 12.el6 | i686 | /var/spool/anacron/cron.daily | cronie-anacron-0:1.4.4-12.el6.i686 | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
cronie-anacron | (none) | 1.4.4 | 12.el6 | i686 | /var/spool/anacron/cron.weekly | cronie-anacron-0:1.4.4-12.el6.i686 | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | true | false | false |
psacct | (none) | 6.3.2 | 63.el6_3.3 | i686 | /var/account/pacct | psacct-0:6.3.2-63.el6_3.3.i686 | pass | fail | not performed | pass | pass | pass | pass | pass | pass | true | false | true | false | false |
gdm | 1 | 2.30.4 | 52.el6 | i686 | /var/run/gdm | gdm-1:2.30.4-52.el6.i686 | pass | fail | not performed | pass | pass | pass | pass | pass | pass | false | false | false | false | false |
gdm | 1 | 2.30.4 | 52.el6 | i686 | /var/log/gdm | gdm-1:2.30.4-52.el6.i686 | pass | fail | not performed | pass | pass | pass | fail | pass | pass | false | false | false | false | false |
Result for Verify File Hashes with RPM
Result: pass
Rule ID: rpm_verify_hashes
Time: 2014-10-07 12:18
Severity: low
The RPM package management system can check the hashes of installed software packages, including many that are important to system security. Run the following command to list which files on the system have hashes that differ from what is expected by the RPM database:
$ rpm -Va | grep '^..5'
A "c" in the second column indicates that a file is a configuration file, which
may appropriately be expected to change. If the file was not expected to
change, investigate the cause of the change using audit logs or other means.
The package can then be reinstalled to restore the file.
Run the following command to determine which package owns the file:
$ rpm -qf FILENAME
The package can be reinstalled from a yum repository using the command:
$ sudo yum reinstall PACKAGENAME
Alternatively, the package can be reinstalled from trusted media using the command:
$ sudo rpm -Uvh PACKAGENAME
The hashes of important files like system executables should match the information given by the RPM database. Executables with erroneous hashes could be a sign of nefarious activity on the system.
Security identifiers
- CCE-27223-7
Result for Add nodev Option to Non-Root Local Partitions
Result: fail
Rule ID: mountopt_nodev_on_nonroot_partitions
Time: 2014-10-07 12:18
Severity: low
The nodev
mount option prevents files from being
interpreted as character or block devices.
Legitimate character and block devices should exist only in
the /dev
directory on the root partition or within chroot
jails built for system services.
Add the nodev
option to the fourth column of
/etc/fstab
for the line which controls mounting of
any non-root local partitions.
The nodev
mount option prevents files from being
interpreted as character or block devices. The only legitimate location
for device files is the /dev
directory located on the root partition.
The only exception to this is chroot jails, for which it is not advised
to set nodev
on these filesystems.
Security identifiers
- CCE-27045-4
nodev on local filesystems
mount point | device | uuid | fs type | mount options | mount options | mount options | mount options | mount options | total space | space used | space left |
/boot | /dev/vda1 | 539e51ca-695f-41ec-96bd-612293252aa7 | ext4 | rw | seclabel | relatime | barrier=1 | data=ordered | 495844 | 33000 | 462844 |
Result for Add nodev Option to Removable Media Partitions
Result: fail
Rule ID: mountopt_nodev_on_removable_partitions
Time: 2014-10-07 12:18
Severity: low
The nodev
mount option prevents files from being
interpreted as character or block devices.
Legitimate character and block devices should exist only in
the /dev
directory on the root partition or within chroot
jails built for system services.
Add the nodev
option to the fourth column of
/etc/fstab
for the line which controls mounting of
any removable media partitions.
The only legitimate location for device files is the /dev
directory
located on the root partition. An exception to this is chroot jails, and it is
not advised to set nodev
on partitions which contain their root
filesystems.
Security identifiers
- CCE-26860-7
Result for Add noexec Option to Removable Media Partitions
Result: fail
Rule ID: mount_option_noexec_removable_partitions
Time: 2014-10-07 12:18
Severity: low
The noexec
mount option prevents the direct
execution of binaries on the mounted filesystem.
Preventing the direct execution of binaries from removable media (such as a USB
key) provides a defense against malicious software that may be present on such
untrusted media.
Add the noexec
option to the fourth column of
/etc/fstab
for the line which controls mounting of
any removable media partitions.
Allowing users to execute binaries from removable media such as USB keys exposes the system to potential compromise.
Security identifiers
- CCE-27196-5
Result for Add nosuid Option to Removable Media Partitions
Result: fail
Rule ID: mountopt_nosuid_on_removable_partitions
Time: 2014-10-07 12:18
Severity: low
The nosuid
mount option prevents set-user-identifier (SUID)
and set-group-identifier (SGID) permissions from taking effect. These permissions
allow users to execute binaries with the same permissions as the owner and group
of the file respectively. Users should not be allowed to introduce SUID and SGID
files into the system via partitions mounted from removeable media.
Add the nosuid
option to the fourth column of
/etc/fstab
for the line which controls mounting of
any removable media partitions.
The presence of SUID and SGID executables should be tightly controlled. Allowing users to introduce SUID or SGID binaries from partitions mounted off of removable media would allow them to introduce their own highly-privileged programs.
Security identifiers
- CCE-27056-1
Result for Add nodev Option to /tmp
Result: fail
Rule ID: mount_option_tmp_nodev
Time: 2014-10-07 12:18
Severity: low
The nodev
mount option can be used to prevent device files from
being created in /tmp
.
Legitimate character and block devices should not exist
within temporary directories like /tmp
.
Add the nodev
option to the fourth column of
/etc/fstab
for the line which controls mounting of
/tmp
.
The only legitimate location for device files is the /dev
directory
located on the root partition. The only exception to this is chroot jails.
Security identifiers
- CCE-26499-4
Result for Add noexec Option to /tmp
Result: fail
Rule ID: mount_option_tmp_noexec
Time: 2014-10-07 12:18
Severity: low
The noexec
mount option can be used to prevent binaries
from being executed out of /tmp
.
Add the noexec
option to the fourth column of
/etc/fstab
for the line which controls mounting of
/tmp
.
Allowing users to execute binaries from world-writable directories
such as /tmp
should never be necessary in normal operation and
can expose the system to potential compromise.
Security identifiers
- CCE-26720-3
Result for Add nosuid Option to /tmp
Result: fail
Rule ID: mount_option_tmp_nosuid
Time: 2014-10-07 12:18
Severity: low
The nosuid
mount option can be used to prevent
execution of setuid programs in /tmp
. The SUID and SGID permissions
should not be required in these world-writable directories.
Add the nosuid
option to the fourth column of
/etc/fstab
for the line which controls mounting of
/tmp
.
The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.
Security identifiers
- CCE-26762-5
Result for Add nodev Option to /dev/shm
Result: fail
Rule ID: mount_option_dev_shm_nodev
Time: 2014-10-07 12:18
Severity: low
The nodev
mount option can be used to prevent creation
of device files in /dev/shm
.
Legitimate character and block devices should not exist
within temporary directories like /dev/shm
.
Add the nodev
option to the fourth column of
/etc/fstab
for the line which controls mounting of
/dev/shm
.
The only legitimate location for device files is the /dev
directory
located on the root partition. The only exception to this is chroot jails.
Security identifiers
- CCE-26778-1
nodev on /dev/shm
mount point | device | uuid | fs type | mount options | mount options | mount options | total space | space used | space left |
/dev/shm | tmpfs | tmpfs | rw | seclabel | relatime | 242366 | 56 | 242310 |
Result for Add noexec Option to /dev/shm
Result: fail
Rule ID: mount_option_dev_shm_noexec
Time: 2014-10-07 12:18
Severity: low
The noexec
mount option can be used to prevent binaries
from being executed out of /dev/shm
.
It can be dangerous to allow the execution of binaries
from world-writable temporary storage directories such as /dev/shm
.
Add the noexec
option to the fourth column of
/etc/fstab
for the line which controls mounting of
/dev/shm
.
Allowing users to execute binaries from world-writable directories
such as /dev/shm
can expose the system to potential compromise.
Security identifiers
- CCE-26622-1
noexec on /dev/shm
mount point | device | uuid | fs type | mount options | mount options | mount options | total space | space used | space left |
/dev/shm | tmpfs | tmpfs | rw | seclabel | relatime | 242366 | 56 | 242310 |
Result for Add nosuid Option to /dev/shm
Result: fail
Rule ID: mount_option_dev_shm_nosuid
Time: 2014-10-07 12:18
Severity: low
The nosuid
mount option can be used to prevent execution
of setuid programs in /dev/shm
. The SUID and SGID permissions should not
be required in these world-writable directories.
Add the nosuid
option to the fourth column of
/etc/fstab
for the line which controls mounting of
/dev/shm
.
The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.
Security identifiers
- CCE-26486-1
nosuid on /dev/shm
mount point | device | uuid | fs type | mount options | mount options | mount options | total space | space used | space left |
/dev/shm | tmpfs | tmpfs | rw | seclabel | relatime | 242366 | 56 | 242310 |
Result for Bind Mount /var/tmp To /tmp
Result: fail
Rule ID: mount_option_var_tmp_bind_var
Time: 2014-10-07 12:18
Severity: low
The /var/tmp
directory is a world-writable directory.
Bind-mount it to /tmp
in order to consolidate temporary storage into
one location protected by the same techniques as /tmp
. To do so, edit
/etc/fstab
and add the following line:
/tmp /var/tmp none rw,nodev,noexec,nosuid,bind 0 0
See the mount(8)
man page for further explanation of bind mounting.
Having multiple locations for temporary storage is not required. Unless absolutely
necessary to meet requirements, the storage location /var/tmp
should be bind mounted to
/tmp
and thus share the same protections.
Security identifiers
- CCE-26582-7
Result for Disable the Automounter
Result: error
Rule ID: service_autofs_disabled
Time: 2014-10-07 12:28
Severity: low
The autofs
daemon mounts and unmounts filesystems, such as user
home directories shared via NFS, on demand. In addition, autofs can be used to handle
removable media, and the default configuration provides the cdrom device as /misc/cd
.
However, this method of providing access to removable media is not common, so autofs
can almost always be disabled if NFS is not in use. Even if NFS is required, it may be
possible to configure filesystem mounts statically by editing /etc/fstab
rather than relying on the automounter.
The autofs
service can be disabled with the following command:
# chkconfig autofs off
Disabling the automounter permits the administrator to
statically control filesystem mounting through /etc/fstab
.
Security identifiers
- CCE-26976-1
Remediation script
#
# Disable autofs for all run levels
#
chkconfig --level 0123456 autofs off
#
# Stop autofs if currently running
#
service autofs stop
Runlevel test
service name | runlevel | start | kill |
autofs | 3 | true | false |
Runlevel test
service name | runlevel | start | kill |
autofs | 4 | true | false |
Runlevel test
service name | runlevel | start | kill |
autofs | 5 | true | false |
Result for Disable Mounting of cramfs
Result: fixed
Rule ID: kernel_module_cramfs_disabled
Time: 2014-10-07 12:28
Severity: low
To configure the system to prevent the cramfs
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install cramfs /bin/false
This effectively prevents usage of this uncommon filesystem.
Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Security identifiers
- CCE-26340-0
Remediation script
echo "install cramfs /bin/false" > /etc/modprobe.d/cramfs.conf
Result for Disable Mounting of freevxfs
Result: fixed
Rule ID: kernel_module_freevxfs_disabled
Time: 2014-10-07 12:28
Severity: low
To configure the system to prevent the freevxfs
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install freevxfs /bin/false
This effectively prevents usage of this uncommon filesystem.
Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Security identifiers
- CCE-26544-7
Remediation script
echo "install freevxfs /bin/false" > /etc/modprobe.d/freevxfs.conf
Result for Disable Mounting of jffs2
Result: fixed
Rule ID: kernel_module_jffs2_disabled
Time: 2014-10-07 12:28
Severity: low
To configure the system to prevent the jffs2
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install jffs2 /bin/false
This effectively prevents usage of this uncommon filesystem.
Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Security identifiers
- CCE-26670-0
Remediation script
echo "install jffs2 /bin/false" > /etc/modprobe.d/jffs2.conf
Result for Disable Mounting of hfs
Result: fixed
Rule ID: kernel_module_hfs_disabled
Time: 2014-10-07 12:28
Severity: low
To configure the system to prevent the hfs
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install hfs /bin/false
This effectively prevents usage of this uncommon filesystem.
Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Security identifiers
- CCE-26800-3
Remediation script
echo "install hfs /bin/false" > /etc/modprobe.d/hfs.conf
Result for Disable Mounting of hfsplus
Result: fixed
Rule ID: kernel_module_hfsplus_disabled
Time: 2014-10-07 12:28
Severity: low
To configure the system to prevent the hfsplus
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install hfsplus /bin/false
This effectively prevents usage of this uncommon filesystem.
Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Security identifiers
- CCE-26361-6
Remediation script
echo "install hfsplus /bin/false" > /etc/modprobe.d/hfsplus.conf
Result for Disable Mounting of squashfs
Result: fixed
Rule ID: kernel_module_squashfs_disabled
Time: 2014-10-07 12:28
Severity: low
To configure the system to prevent the squashfs
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install squashfs /bin/false
This effectively prevents usage of this uncommon filesystem.
Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Security identifiers
- CCE-26404-4
Remediation script
echo "install squashfs /bin/false" > /etc/modprobe.d/squashfs.conf
Result for Disable Mounting of udf
Result: fixed
Rule ID: kernel_module_udf_disabled
Time: 2014-10-07 12:28
Severity: low
To configure the system to prevent the udf
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install udf /bin/false
This effectively prevents usage of this uncommon filesystem.
Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Security identifiers
- CCE-26677-5
Remediation script
echo "install udf /bin/false" > /etc/modprobe.d/udf.conf
Result for Verify User Who Owns shadow File
Result: pass
Rule ID: userowner_shadow_file
Time: 2014-10-07 12:18
Severity: medium
To properly set the owner of /etc/shadow
, run the command:
# chown root /etc/shadow
The /etc/shadow
file contains the list of local
system accounts and stores password hashes. Protection of this file is
critical for system security. Failure to give ownership of this file
to root provides the designated owner with access to sensitive information
which could weaken the system security posture.
Security identifiers
- CCE-26947-2
Remediation script
chown root /etc/shadow
Result for Verify Group Who Owns shadow File
Result: pass
Rule ID: groupowner_shadow_file
Time: 2014-10-07 12:18
Severity: medium
To properly set the group owner of /etc/shadow
, run the command:
# chgrp root /etc/shadow
The /etc/shadow
file stores password hashes. Protection of this file is
critical for system security.
Security identifiers
- CCE-26967-0
Remediation script
chgrp root /etc/shadow
Result for Verify Permissions on shadow File
Result: pass
Rule ID: file_permissions_etc_shadow
Time: 2014-10-07 12:18
Severity: medium
To properly set the permissions of /etc/shadow
, run the command:
# chmod 0000 /etc/shadow
The /etc/shadow
file contains the list of local
system accounts and stores password hashes. Protection of this file is
critical for system security. Failure to give ownership of this file
to root provides the designated owner with access to sensitive information
which could weaken the system security posture.
Security identifiers
- CCE-26992-8
Remediation script
chmod 0000 /etc/shadow
Result for Verify User Who Owns group File
Result: pass
Rule ID: file_owner_etc_group
Time: 2014-10-07 12:18
Severity: medium
To properly set the owner of /etc/group
, run the command:
# chown root /etc/group
The /etc/group
file contains information regarding groups that are configured
on the system. Protection of this file is important for system security.
Security identifiers
- CCE-26822-7
Remediation script
chown root /etc/group
Result for Verify Group Who Owns group File
Result: pass
Rule ID: file_groupowner_etc_group
Time: 2014-10-07 12:18
Severity: medium
To properly set the group owner of /etc/group
, run the command:
# chgrp root /etc/group
The /etc/group
file contains information regarding groups that are configured
on the system. Protection of this file is important for system security.
Security identifiers
- CCE-26930-8
Remediation script
chgrp root /etc/group
Result for Verify Permissions on group File
Result: pass
Rule ID: file_permissions_etc_group
Time: 2014-10-07 12:18
Severity: medium
To properly set the permissions of /etc/group
, run the command:
# chmod 644 /etc/group
The /etc/group
file contains information regarding groups that are configured
on the system. Protection of this file is important for system security.
Security identifiers
- CCE-26954-8
Remediation script
chmod 644 /etc/group
Result for Verify User Who Owns gshadow File
Result: pass
Rule ID: file_owner_etc_gshadow
Time: 2014-10-07 12:18
Severity: medium
To properly set the owner of /etc/gshadow
, run the command:
# chown root /etc/gshadow
The /etc/gshadow
file contains group password hashes. Protection of this file
is critical for system security.
Security identifiers
- CCE-27026-4
Remediation script
chown root /etc/gshadow
Result for Verify Group Who Owns gshadow File
Result: pass
Rule ID: file_groupowner_etc_gshadow
Time: 2014-10-07 12:18
Severity: medium
To properly set the group owner of /etc/gshadow
, run the command:
# chgrp root /etc/gshadow
The /etc/gshadow
file contains group password hashes. Protection of this file
is critical for system security.
Security identifiers
- CCE-26975-3
Remediation script
chgrp root /etc/gshadow
Result for Verify Permissions on gshadow File
Result: pass
Rule ID: file_permissions_etc_gshadow
Time: 2014-10-07 12:18
Severity: medium
To properly set the permissions of /etc/gshadow
, run the command:
# chmod 0000 /etc/gshadow
The /etc/gshadow
file contains group password hashes. Protection of this file
is critical for system security.
Security identifiers
- CCE-26951-4
Remediation script
chmod 0000 /etc/gshadow
Result for Verify User Who Owns passwd File
Result: pass
Rule ID: file_owner_etc_passwd
Time: 2014-10-07 12:18
Severity: medium
To properly set the owner of /etc/passwd
, run the command:
# chown root /etc/passwd
The /etc/passwd
file contains information about the users that are configured on
the system. Protection of this file is critical for system security.
Security identifiers
- CCE-26953-0
Remediation script
chown root /etc/passwd
Result for Verify Group Who Owns passwd File
Result: pass
Rule ID: file_groupowner_etc_passwd
Time: 2014-10-07 12:18
Severity: medium
To properly set the group owner of /etc/passwd
, run the command:
# chgrp root /etc/passwd
The /etc/passwd
file contains information about the users that are configured on
the system. Protection of this file is critical for system security.
Security identifiers
- CCE-26856-5
Remediation script
chgrp root /etc/passwd
Result for Verify Permissions on passwd File
Result: pass
Rule ID: file_permissions_etc_passwd
Time: 2014-10-07 12:18
Severity: medium
To properly set the permissions of /etc/passwd
, run the command:
# chmod 0644 /etc/passwd
If the /etc/passwd
file is writable by a group-owner or the
world the risk of its compromise is increased. The file contains the list of
accounts on the system and associated information, and protection of this file
is critical for system security.
Security identifiers
- CCE-26868-0
Remediation script
chmod 0644 /etc/passwd
Result for Verify that All World-Writable Directories Have Sticky Bits Set
Result: pass
Rule ID: sticky_world_writable_dirs
Time: 2014-10-07 12:20
Severity: low
When the so-called 'sticky bit' is set on a directory,
only the owner of a given file may remove that file from the
directory. Without the sticky bit, any user with write access to a
directory may remove any file in the directory. Setting the sticky
bit prevents users from removing each other's files. In cases where
there is no reason for a directory to be world-writable, a better
solution is to remove that permission rather than to set the sticky
bit. However, if a directory is used by a particular application,
consult that application's documentation instead of blindly
changing modes.
To set the sticky bit on a world-writable directory DIR, run the
following command:
$ sudo chmod +t DIR
Failing to set the sticky bit on public directories allows unauthorized users to delete files in the directory structure.
The only authorized public directories are those temporary directories supplied with the system,
or those designed to be temporary file repositories. The setting is normally reserved for directories
used by the system, by users for temporary file storage (such as /tmp
), and for directories
requiring global read/write access.
Security identifiers
- CCE-26840-9
Remediation script
df --local -P | awk {'if (NR!=1) print $6'} \
| xargs -I '{}' find '{}' -xdev -type d \
\( -perm -0002 -a ! -perm -1000 \) 2>/dev/null \
| xargs chmod a+t
Result for Ensure No World-Writable Files Exist
Result: pass
Rule ID: world_writeable_files
Time: 2014-10-07 12:20
Severity: medium
It is generally a good idea to remove global (other) write access to a file when it is discovered. However, check with documentation for specific applications before making changes. Also, monitor for recurring world-writable files, as these may be symptoms of a misconfigured application or user account.
Data in world-writable files can be modified by any user on the system. In almost all circumstances, files can be configured using a combination of user and group permissions to support whatever legitimate access is needed without the risk caused by world-writable files.
Security identifiers
- CCE-26910-0
Result for Ensure All SGID Executables Are Authorized
Result: pass
Rule ID: no_unpackaged_sgid_files
Time: 2014-10-07 12:21
Severity: low
The SGID (set group id) bit should be set only on files that were installed via authorized means. A straightforward means of identifying unauthorized SGID files is determine if any were not installed as part of an RPM package, which is cryptographically verified. Investigate the origin of any unpackaged SGID files.
Executable files with the SGID permission run with the privileges of the owner of the file. SGID files of uncertain provenance could allow for unprivileged users to elevate privileges. The presence of these files should be strictly controlled on the system.
Security identifiers
- CCE-26769-0
Result for Ensure All SUID Executables Are Authorized
Result: pass
Rule ID: no_unpackaged_suid_files
Time: 2014-10-07 12:21
Severity: low
The SUID (set user id) bit should be set only on files that were installed via authorized means. A straightforward means of identifying unauthorized SGID files is determine if any were not installed as part of an RPM package, which is cryptographically verified. Investigate the origin of any unpackaged SUID files.
Executable files with the SUID permission run with the privileges of the owner of the file. SUID files of uncertain provenance could allow for unprivileged users to elevate privileges. The presence of these files should be strictly controlled on the system.
Security identifiers
- CCE-26497-8
Result for Ensure All Files Are Owned by a User
Result: pass
Rule ID: no_files_unowned_by_user
Time: 2014-10-07 12:22
Severity: low
If any files are not owned by a user, then the cause of their lack of ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate user.
Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.
Security identifiers
- CCE-27032-2
Result for Ensure All Files Are Owned by a Group
Result: unknown
Rule ID: no_files_unowned_by_group
Time: 2014-10-07 12:26
Severity: low
If any files are not owned by a group, then the cause of their lack of group-ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate group.
Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.
Security identifiers
- CCE-26872-2
Result for Ensure All World-Writable Directories Are Owned by a System Account
Result: pass
Rule ID: world_writable_files_system_ownership
Time: 2014-10-07 12:26
Severity: low
All directories in local partitions which are world-writable should be owned by root or another system account. If any world-writable directories are not owned by a system account, this should be investigated. Following this, the files should be deleted or assigned to an appropriate group.
Allowing a user account to own a world-writable directory is undesirable because it allows the owner of that directory to remove or replace any files that may be placed in the directory by other users.
Security identifiers
- CCE-26642-9
Result for Set Daemon Umask
Result: fixed
Rule ID: umask_for_daemons
Time: 2014-10-07 12:28
Severity: low
The file /etc/init.d/functions
includes initialization
parameters for most or all daemons started at boot time. The default umask of
022 prevents creation of group- or world-writable files. To set the default
umask for daemons, edit the following line, inserting 022 or 027 for
umask appropriately:
umask 027
Setting the umask to too restrictive a setting can cause serious errors at
runtime. Many daemons on the system already individually restrict themselves to
a umask of 077 in their own init scripts.
The umask influences the permissions assigned to files created by a process at run time. An unnecessarily permissive umask could result in files being created with insecure permissions.
Security identifiers
- CCE-27031-4
Remediation script
var_umask_for_daemons="027"
grep -q ^umask /etc/init.d/functions && \
sed -i "s/umask.*/umask $var_umask_for_daemons/g" /etc/init.d/functions
if ! [ $? -eq 0 ]; then
echo "umask $var_umask_for_daemons" >> /etc/init.d/functions
fi
Result for Disable Core Dumps for All Users
Result: fixed
Rule ID: disable_users_coredumps
Time: 2014-10-07 12:28
Severity: low
To disable core dumps for all users, add the following line to
/etc/security/limits.conf
:
* hard core 0
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.
Security identifiers
- CCE-27033-0
Remediation script
echo "* hard core 0" >> /etc/security/limits.conf
Result for Disable Core Dumps for SUID programs
Result: fixed
Rule ID: sysctl_fs_suid_dumpable
Time: 2014-10-07 12:28
Severity: low
To set the runtime status of the fs.suid_dumpable
kernel parameter,
run the following command:
# sysctl -w fs.suid_dumpable=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
fs.suid_dumpable = 0
The core dump of a setuid program is more likely to contain sensitive data, as the program itself runs with greater privileges than the user who initiated execution of the program. Disabling the ability for any setuid program to write a core file decreases the risk of unauthorized access of such data.
Security identifiers
- CCE-27044-7
Remediation script
#
# Set runtime for fs.suid_dumpable
#
sysctl -q -n -w fs.suid_dumpable=0
#
# If fs.suid_dumpable present in /etc/sysctl.conf, change value to "0"
# else, add "fs.suid_dumpable = 0" to /etc/sysctl.conf
#
if grep --silent ^fs.suid_dumpable /etc/sysctl.conf ; then
sed -i 's/^fs.suid_dumpable.*/fs.suid_dumpable = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set fs.suid_dumpable to 0 per security requirements" >> /etc/sysctl.conf
echo "fs.suid_dumpable = 0" >> /etc/sysctl.conf
fi
Result for Enable ExecShield
Result: fixed
Rule ID: sysctl_kernel_exec_shield
Time: 2014-10-07 12:28
Severity: medium
To set the runtime status of the kernel.exec-shield
kernel parameter,
run the following command:
# sysctl -w kernel.exec-shield=1
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
kernel.exec-shield = 1
ExecShield uses the segmentation feature on all x86 systems to prevent execution in memory higher than a certain address. It writes an address as a limit in the code segment descriptor, to control where code can be executed, on a per-process basis. When the kernel places a process's memory regions such as the stack and heap higher than this address, the hardware prevents execution in that address range.
Security identifiers
- CCE-27007-4
Remediation script
#
# Set runtime for kernel.exec-shield
#
sysctl -q -n -w kernel.exec-shield=1
#
# If kernel.exec-shield present in /etc/sysctl.conf, change value to "1"
# else, add "kernel.exec-shield = 1" to /etc/sysctl.conf
#
if grep --silent ^kernel.exec-shield /etc/sysctl.conf ; then
sed -i 's/^kernel.exec-shield.*/kernel.exec-shield = 1/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set kernel.exec-shield to 1 per security requirements" >> /etc/sysctl.conf
echo "kernel.exec-shield = 1" >> /etc/sysctl.conf
fi
Result for Enable Randomized Layout of Virtual Address Space
Result: fixed
Rule ID: sysctl_kernel_randomize_va_space
Time: 2014-10-07 12:28
Severity: medium
To set the runtime status of the kernel.randomize_va_space
kernel parameter,
run the following command:
# sysctl -w kernel.randomize_va_space=2
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
kernel.randomize_va_space = 2
Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to re-purpose it using return oriented programming (ROP) techniques.
Security identifiers
- CCE-26999-3
Remediation script
#
# Set runtime for kernel.randomize_va_space
#
sysctl -q -n -w kernel.randomize_va_space=2
#
# If kernel.randomize_va_space present in /etc/sysctl.conf, change value to "2"
# else, add "kernel.randomize_va_space = 2" to /etc/sysctl.conf
#
if grep --silent ^kernel.randomize_va_space /etc/sysctl.conf ; then
sed -i 's/^kernel.randomize_va_space.*/kernel.randomize_va_space = 2/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set kernel.randomize_va_space to 2 per security requirements" >> /etc/sysctl.conf
echo "kernel.randomize_va_space = 2" >> /etc/sysctl.conf
fi
Result for Install PAE Kernel on Supported 32-bit x86 Systems
Result: notchecked
Rule ID: install_PAE_kernel_on_x86-32
Time: 2014-10-07 12:26
Severity: low
Systems that are using the 64-bit x86 kernel package do not need to install the kernel-PAE package because the 64-bit x86 kernel already includes this support. However, if the system is 32-bit and also supports the PAE and NX features as determined in the previous section, the kernel-PAE package should be installed to enable XD or NX support:
$ sudo yum install kernel-PAE
The installation process should also have configured the
bootloader to load the new kernel at boot. Verify this at reboot
and modify /etc/grub.conf
if necessary.
The kernel-PAE package should not be installed on older systems that do not support the XD or NX bit, as this may prevent them from booting.
On 32-bit systems that support the XD or NX bit, the vendor-supplied PAE kernel is required to enable either Execute Disable (XD) or No Execute (NX) support.
Security identifiers
- CCE-27010-8
Result for Ensure SELinux Not Disabled in /etc/grub.conf
Result: pass
Rule ID: enable_selinux_bootloader
Time: 2014-10-07 12:26
Severity: medium
SELinux can be disabled at boot time by an argument in
/etc/grub.conf
.
Remove any instances of selinux=0
from the kernel arguments in that
file to prevent SELinux from being disabled at boot.
Disabling a major host protection feature, such as SELinux, at boot time prevents it from confining system services at boot time. Further, it increases the chances that it will remain off during system operation.
Security identifiers
- CCE-26956-3
Remediation script
sed -i "s/selinux=0//gI" /etc/grub.conf
sed -i "s/enforcing=0//gI" /etc/grub.conf
Result for Ensure SELinux State is Enforcing
Result: pass
Rule ID: selinux_state
Time: 2014-10-07 12:26
Severity: medium
The SELinux state should be set to enforcing
at
system boot time. In the file /etc/selinux/config
, add or correct the
following line to configure the system to boot into enforcing mode:
SELINUX=enforcing
Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.
Security identifiers
- CCE-26969-6
Remediation script
var_selinux_state="enforcing"
grep -q ^SELINUX= /etc/selinux/config && \
sed -i "s/SELINUX=.*/SELINUX=$var_selinux_state/g" /etc/selinux/config
if ! [ $? -eq 0 ]; then
echo "SELINUX=$var_selinux_state" >> /etc/selinux/config
fi
Result for Configure SELinux Policy
Result: pass
Rule ID: selinux_policytype
Time: 2014-10-07 12:26
Severity: low
The SELinux targeted
policy is appropriate for
general-purpose desktops and servers, as well as systems in many other roles.
To configure the system to use this policy, add or correct the following line
in /etc/selinux/config
:
SELINUXTYPE=targeted
Other policies, such as mls
, provide additional security labeling
and greater confinement but are not compatible with many general-purpose
use cases.
Setting the SELinux policy to targeted
or a more specialized policy
ensures the system will confine processes that are likely to be
targeted for exploitation, such as network or system services.
Security identifiers
- CCE-26875-5
Remediation script
var_selinux_policy_name="targeted"
grep -q ^SELINUXTYPE /etc/selinux/config && \
sed -i "s/SELINUXTYPE=.*/SELINUXTYPE=$var_selinux_policy_name/g" /etc/selinux/config
if ! [ $? -eq 0 ]; then
echo "SELINUXTYPE=$var_selinux_policy_name" >> /etc/selinux/config
fi
Result for Ensure No Daemons are Unconfined by SELinux
Result: notchecked
Rule ID: selinux_confinement_of_daemons
Time: 2014-10-07 12:26
Severity: medium
Daemons for which the SELinux policy does not contain rules will inherit the
context of the parent process. Because daemons are launched during
startup and descend from the init
process, they inherit the initrc_t
context.
To check for unconfined daemons, run the following command:
$ sudo ps -eZ | egrep "initrc" | egrep -vw "tr|ps|egrep|bash|awk" | tr ':' ' ' | awk '{ print $NF }'
It should produce no output in a well-configured system.
Daemons which run with the initrc_t
context may cause AVC denials,
or allow privileges that the daemon does not require.
Security identifiers
- CCE-27111-4
Result for Ensure No Device Files are Unlabeled by SELinux
Result: pass
Rule ID: selinux_all_devicefiles_labeled
Time: 2014-10-07 12:26
Severity: low
Device files, which are used for communication with important
system resources, should be labeled with proper SELinux types. If any device
files carry the SELinux type unlabeled_t
, investigate the cause and
correct the file's context.
If a device file carries the SELinux type unlabeled_t
, then SELinux
cannot properly restrict access to the device file.
Security identifiers
- CCE-26774-0
Result for Restrict Virtual Console Root Logins
Result: fixed
Rule ID: securetty_root_login_console_only
Time: 2014-10-07 12:28
Severity: medium
To restrict root logins through the (deprecated) virtual console devices,
ensure lines of this form do not appear in /etc/securetty
:
vc/1
vc/2
vc/3
vc/4
Preventing direct root login to virtual console devices helps ensure accountability for actions taken on the system using the root account.
Security identifiers
- CCE-26855-7
Remediation script
sed -i '/^vc\//d' /etc/securetty
Result for Restrict Serial Port Root Logins
Result: pass
Rule ID: restrict_serial_port_logins
Time: 2014-10-07 12:26
Severity: low
To restrict root logins on serial ports,
ensure lines of this form do not appear in /etc/securetty
:
ttyS0
ttyS1
Preventing direct root login to serial port interfaces helps ensure accountability for actions taken on the systems using the root account.
Security identifiers
- CCE-27047-0
Result for Verify Only Root Has UID 0
Result: pass
Rule ID: accounts_no_uid_except_zero
Time: 2014-10-07 12:26
Severity: medium
If any account other than root has a UID of 0, this misconfiguration should be investigated and the accounts other than root should be removed or have their UID changed.
An account has root authority if it has a UID of 0. Multiple accounts with a UID of 0 afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.
Security identifiers
- CCE-26971-2
Remediation script
awk -F: '$3 == 0 && $1 != "root" { print $1 }' /etc/passwd | xargs passwd -l
Result for Prevent Log In to Accounts With Empty Password
Result: fixed
Rule ID: no_empty_passwords
Time: 2014-10-07 12:28
Severity: high
If an account is configured for password authentication
but does not have an assigned password, it may be possible to log
into the account without authentication. Remove any instances of the nullok
option in /etc/pam.d/system-auth
to
prevent logins with empty passwords.
If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Security identifiers
- CCE-27038-9
Remediation script
sed --follow-symlinks -i 's/\<nullok\>//g' /etc/pam.d/system-auth
Result for Verify All Account Password Hashes are Shadowed
Result: pass
Rule ID: accounts_password_all_shadowed
Time: 2014-10-07 12:26
Severity: medium
If any password hashes are stored in /etc/passwd
(in the second field,
instead of an x
), the cause of this misconfiguration should be
investigated. The account should have its password reset and the hash should be
properly stored, or the account should be deleted entirely.
The hashes for all user account passwords should be stored in
the file /etc/shadow
and never in /etc/passwd
,
which is readable by all users.
Security identifiers
- CCE-26476-2
Result for Set Password Minimum Length in login.defs
Result: fixed
Rule ID: accounts_password_minlen_login_defs
Time: 2014-10-07 12:28
Severity: medium
To specify password length requirements for new accounts,
edit the file /etc/login.defs
and add or correct the following
lines:
PASS_MIN_LEN 12
The DoD requirement is
14
.
The FISMA requirement is 12
.
If a program consults /etc/login.defs
and also another PAM module
(such as pam_cracklib
) during a password change operation,
then the most restrictive must be satisfied. See PAM section
for more information about enforcing password quality requirements.
Requiring a minimum password length makes password cracking attacks more difficult by ensuring a larger search space. However, any security benefit from an onerous requirement must be carefully weighed against usability problems, support costs, or counterproductive behavior that may result.
Security identifiers
- CCE-27002-5
Remediation script
var_accounts_password_minlen_login_defs="12"
grep -q ^PASS_MIN_LEN /etc/login.defs && \
sed -i "s/PASS_MIN_LEN.*/PASS_MIN_LEN $var_accounts_password_minlen_login_defs/g" /etc/login.defs
if ! [ $? -eq 0 ]; then
echo "PASS_MIN_LEN $var_accounts_password_minlen_login_defs" >> /etc/login.defs
fi
Result for Set Password Maximum Age
Result: fixed
Rule ID: accounts_maximum_age_login_defs
Time: 2014-10-07 12:28
Severity: medium
To specify password maximum age for new accounts,
edit the file /etc/login.defs
and add or correct the following line:
PASS_MAX_DAYS 60
A value of 180 days is sufficient for many environments.
The DoD requirement is 60.
Setting the password maximum age ensures users are required to periodically change their passwords. This could possibly decrease the utility of a stolen password. Requiring shorter password lifetimes increases the risk of users writing down the password in a convenient location subject to physical compromise.
Security identifiers
- CCE-26985-2
Remediation script
var_accounts_maximum_age_login_defs="60"
grep -q ^PASS_MAX_DAYS /etc/login.defs && \
sed -i "s/PASS_MAX_DAYS.*/PASS_MAX_DAYS $var_accounts_maximum_age_login_defs/g" /etc/login.defs
if ! [ $? -eq 0 ]; then
echo "PASS_MAX_DAYS $var_accounts_maximum_age_login_defs" >> /etc/login.defs
fi
Result for Set Password Warning Age
Result: fixed
Rule ID: accounts_password_warn_age_login_defs
Time: 2014-10-07 12:28
Severity: low
To specify how many days prior to password
expiration that a warning will be issued to users,
edit the file /etc/login.defs
and add or correct
the following line:
PASS_WARN_AGE 14
The DoD requirement is 7.
Setting the password warning age enables users to make the change at a practical time.
Security identifiers
- CCE-26988-6
Remediation script
var_accounts_password_warn_age_login_defs="14"
grep -q ^PASS_WARN_AGE /etc/login.defs && \
sed -i "s/PASS_WARN_AGE.*/PASS_WARN_AGE $var_accounts_password_warn_age_login_defs/g" /etc/login.defs
if ! [ $? -eq 0 ]; then
echo "PASS_WARN_AGE $var_accounts_password_warn_age_login_defs" >> /etc/login.defs
fi
Result for Set Account Expiration Following Inactivity
Result: fixed
Rule ID: account_disable_post_pw_expiration
Time: 2014-10-07 12:28
Severity: low
To specify the number of days after a password expires (which
signifies inactivity) until an account is permanently disabled, add or correct
the following lines in /etc/default/useradd
, substituting
NUM_DAYS
appropriately:
INACTIVE=NUM_DAYS
A value of 35 is recommended.
If a password is currently on the
verge of expiration, then 35 days remain until the account is automatically
disabled. However, if the password will not expire for another 60 days, then 95
days could elapse until the account would be automatically disabled. See the
useradd
man page for more information. Determining the inactivity
timeout must be done with careful consideration of the length of a "normal"
period of inactivity for users in the particular environment. Setting
the timeout too low incurs support costs and also has the potential to impact
availability of the system to legitimate users.
Disabling inactive accounts ensures that accounts which may not have been responsibly removed are not available to attackers who may have compromised their credentials.
Security identifiers
- CCE-27283-1
Remediation script
var_account_disable_post_pw_expiration="30"
grep -q ^INACTIVE /etc/default/useradd && \
sed -i "s/INACTIVE.*/INACTIVE=$var_account_disable_post_pw_expiration/g" /etc/default/useradd
if ! [ $? -eq 0 ]; then
echo "INACTIVE=$var_account_disable_post_pw_expiration" >> /etc/default/useradd
fi
Result for Set Password Retry Prompts Permitted Per-Session
Result: pass
Rule ID: accounts_password_pam_retry
Time: 2014-10-07 12:26
Severity: low
To configure the number of retry prompts that are permitted per-session:
Edit the pam_cracklib.so
statement in /etc/pam.d/system-auth
to
show retry=3
, or a lower value if site policy is more restrictive.
The DoD requirement is a maximum of 3 prompts per session.
Setting the password retry prompts that are permitted on a per-session basis to a low value requires some software, such as SSH, to re-connect. This can slow down and draw additional attention to some types of password-guessing attacks. Note that this is different from account lockout, which is provided by the pam_faillock module.
Security identifiers
- CCE-27123-9
Result for Set Password Strength Minimum Digit Characters
Result: fixed
Rule ID: accounts_password_pam_dcredit
Time: 2014-10-07 12:28
Severity: low
The pam_cracklib module's dcredit
parameter controls requirements for
usage of digits in a password. When set to a negative number, any password will be required to
contain that many digits. When set to a positive number, pam_cracklib will grant +1 additional
length credit for each digit.
Add dcredit=-1
after pam_cracklib.so to require use of a digit in passwords.
Requiring digits makes password guessing attacks more difficult by ensuring a larger search space.
Security identifiers
- CCE-26374-9
Remediation script
var_password_pam_dcredit="-1"
if grep -q "dcredit=" /etc/pam.d/system-auth; then
sed -i --follow-symlink "s/\(dcredit *= *\).*/\1$var_password_pam_dcredit/" /etc/pam.d/system-auth
else
sed -i --follow-symlink "/pam_cracklib.so/ s/$/ dcredit=$var_password_pam_dcredit/" /etc/pam.d/system-auth
fi
Result for Set Password Strength Minimum Uppercase Characters
Result: fixed
Rule ID: accounts_password_pam_ucredit
Time: 2014-10-07 12:28
Severity: low
The pam_cracklib module's ucredit=
parameter controls requirements for
usage of uppercase letters in a password. When set to a negative number, any password will be required to
contain that many uppercase characters. When set to a positive number, pam_cracklib will grant +1 additional
length credit for each uppercase character.
Add ucredit=-1
after pam_cracklib.so to require use of an upper case character in passwords.
Requiring a minimum number of uppercase characters makes password guessing attacks more difficult by ensuring a larger search space.
Security identifiers
- CCE-26601-5
Remediation script
var_password_pam_ucredit="-1"
if grep -q "ucredit=" /etc/pam.d/system-auth; then
sed -i --follow-symlink "s/\(ucredit *= *\).*/\1$var_password_pam_ucredit/" /etc/pam.d/system-auth
else
sed -i --follow-symlink "/pam_cracklib.so/ s/$/ ucredit=$var_password_pam_ucredit/" /etc/pam.d/system-auth
fi
Result for Set Password Strength Minimum Special Characters
Result: fixed
Rule ID: accounts_password_pam_ocredit
Time: 2014-10-07 12:28
Severity: low
The pam_cracklib module's ocredit=
parameter controls requirements for
usage of special (or ``other'') characters in a password. When set to a negative number, any password will be required to
contain that many special characters. When set to a positive number, pam_cracklib will grant +1 additional
length credit for each special character.
Add ocredit=-1
after pam_cracklib.so to require use of a special character in passwords.
Requiring a minimum number of special characters makes password guessing attacks more difficult by ensuring a larger search space.
Security identifiers
- CCE-26409-3
Remediation script
var_password_pam_ocredit="-1"
if grep -q "ocredit=" /etc/pam.d/system-auth; then
sed -i --follow-symlink "s/\(ocredit *= *\).*/\1$var_password_pam_ocredit/" /etc/pam.d/system-auth
else
sed -i --follow-symlink "/pam_cracklib.so/ s/$/ ocredit=$var_password_pam_ocredit/" /etc/pam.d/system-auth
fi
Result for Set Password Strength Minimum Lowercase Characters
Result: fixed
Rule ID: accounts_password_pam_lcredit
Time: 2014-10-07 12:28
Severity: low
The pam_cracklib module's lcredit=
parameter controls requirements for
usage of lowercase letters in a password. When set to a negative number, any password will be required to
contain that many lowercase characters. When set to a positive number, pam_cracklib will grant +1 additional
length credit for each lowercase character.
Add lcredit=-1
after pam_cracklib.so to require use of a lowercase character in passwords.
Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space.
Security identifiers
- CCE-26631-2
Remediation script
var_password_pam_lcredit="-1"
if grep -q "lcredit=" /etc/pam.d/system-auth; then
sed -i --follow-symlink "s/\(lcredit *= *\).*/\1$var_password_pam_lcredit/" /etc/pam.d/system-auth
else
sed -i --follow-symlink "/pam_cracklib.so/ s/$/ lcredit=$var_password_pam_lcredit/" /etc/pam.d/system-auth
fi
Result for Set Password Strength Minimum Different Characters
Result: fixed
Rule ID: accounts_password_pam_difok
Time: 2014-10-07 12:28
Severity: low
The pam_cracklib module's difok
parameter controls requirements for
usage of different characters during a password change.
Add difok=3
after pam_cracklib.so to require differing
characters when changing passwords. The DoD requirement is 4
.
Requiring a minimum number of different characters during password changes ensures that newly changed passwords should not resemble previously compromised ones. Note that passwords which are changed on compromised systems will still be compromised, however.
Security identifiers
- CCE-26615-5
Remediation script
var_password_pam_difok="3"
if grep -q "difok=" /etc/pam.d/system-auth; then
sed -i --follow-symlink "s/\(difok *= *\).*/\1$var_password_pam_difok/" /etc/pam.d/system-auth
else
sed -i --follow-symlink "/pam_cracklib.so/ s/$/ difok=$var_password_pam_difok/" /etc/pam.d/system-auth
fi
Result for Set Deny For Failed Password Attempts
Result: error
Rule ID: accounts_passwords_pam_faillock_deny
Time: 2014-10-07 12:28
Severity: medium
To configure the system to lock out accounts after a number of incorrect login
attempts using pam_faillock.so
:
Add the following lines immediately below the pam_unix.so
statement in AUTH
section of
both /etc/pam.d/system-auth
and /etc/pam.d/password-auth:
auth [default=die] pam_faillock.so authfail deny=5 unlock_time=604800 fail_interval=900
auth required pam_faillock.so authsucc deny=5 unlock_time=604800 fail_interval=900
Locking out user accounts after a number of incorrect attempts prevents direct password guessing attacks.
Security identifiers
- CCE-26844-1
Remediation script
var_accounts_passwords_pam_faillock_deny="5"
for pamFile in "/etc/pam.d/system-auth /etc/pam.d/password-auth"
do
if grep -q "^auth.*[default=die].*pam_faillock.so.*authfail.*deny=" $pamFile; then
sed -i --follow-symlink "s/\(^auth.*[default=die].*pam_faillock.so.*authfail.*\)\(deny *= *\).*/\1\2$var_accounts_passwords_pam_faillock_deny/" $pamFile
else
sed -i --follow-symlink "/^auth.*[default=die].*pam_faillock.so.*authfail/ s/$/ deny=$var_accounts_passwords_pam_faillock_deny/" $pamFile
fi
if grep -q "^auth.*[default=die].*pam_faillock.so.*authsucc.*deny=" /etc/pam.d/system-auth; then
sed -i --follow-symlink "s/\(^auth.*[default=die].*pam_faillock.so.*authsucc.*\)\(deny *= *\).*/\1\2$var_accounts_passwords_pam_faillock_deny/" $pamFile
else
sed -i --follow-symlink "/^auth.*[default=die].*pam_faillock.so.*authsucc/ s/$/ deny=$var_accounts_passwords_pam_faillock_deny/" $pamFile
fi
done
Result for Limit Password Reuse
Result: fixed
Rule ID: accounts_password_pam_unix_remember
Time: 2014-10-07 12:28
Severity: medium
Do not allow users to reuse recent passwords. This can
be accomplished by using the remember
option for the pam_unix
PAM
module. In the file /etc/pam.d/system-auth
, append remember=24
to the
line which refers to the pam_unix.so
module, as shown:
password sufficient pam_unix.so existing_options remember=24
The DoD STIG requirement is 5 passwords.
Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.
Security identifiers
- CCE-26741-9
Remediation script
var_password_pam_unix_remember="24"
if grep -q "remember=" /etc/pam.d/system-auth; then
sed -i --follow-symlink "s/\(remember *= *\).*/\1$var_password_pam_unix_remember/" /etc/pam.d/system-auth
else
sed -i --follow-symlink "/^password[[:space:]]\+sufficient[[:space:]]\+pam_unix.so/ s/$/ remember=$var_password_pam_unix_remember/" /etc/pam.d/system-auth
fi
Result for Set Password Hashing Algorithm in /etc/pam.d/system-auth
Result: pass
Rule ID: set_password_hashing_algorithm_systemauth
Time: 2014-10-07 12:26
Severity: medium
In /etc/pam.d/system-auth
, the password
section of
the file controls which PAM modules execute during a password change.
Set the pam_unix.so
module in the
password
section to include the argument sha512
, as shown below:
password sufficient pam_unix.so sha512 other arguments...
This will help ensure when local users change their passwords, hashes for the new
passwords will be generated using the SHA-512 algorithm.
This is the default.
Using a stronger hashing algorithm makes password cracking attacks more difficult.
Security identifiers
- CCE-26303-8
Remediation script
if ! grep -q "^password.*sufficient.*pam_unix.so.*sha512" /etc/pam.d/system-auth; then
sed -i --follow-symlink "/^password.*sufficient.*pam_unix.so/ s/$/ sha512/" /etc/pam.d/system-auth
fi
Result for Set Password Hashing Algorithm in /etc/login.defs
Result: pass
Rule ID: set_password_hashing_algorithm_logindefs
Time: 2014-10-07 12:26
Severity: medium
In /etc/login.defs
, add or correct the following line to ensure
the system will use SHA-512 as the hashing algorithm:
ENCRYPT_METHOD SHA512
Using a stronger hashing algorithm makes password cracking attacks more difficult.
Security identifiers
- CCE-27228-6
Remediation script
if grep --silent ^ENCRYPT_METHOD /etc/login.defs ; then
sed -i 's/^ENCRYPT_METHOD.*/ENCRYPT_METHOD SHA512/g' /etc/login.defs
else
echo "" >> /etc/login.defs
echo "ENCRYPT_METHOD SHA512" >> /etc/login.defs
fi
Result for Ensure that Root's Path Does Not Include Relative Paths or Null Directories
Result: pass
Rule ID: root_path_no_dot
Time: 2014-10-07 12:26
Severity: low
Ensure that none of the directories in root's path is equal to a single
.
character, or
that it contains any instances that lead to relative path traversal, such as
..
or beginning a path without the slash (/
) character.
Also ensure that there are no "empty" elements in the path, such as in these examples:
PATH=:/bin
PATH=/bin:
PATH=/bin::/sbin
These empty elements have the same effect as a single .
character.
Including these entries increases the risk that root could execute code from an untrusted location.
Security identifiers
- CCE-26826-8
Result for Ensure that Root's Path Does Not Include World or Group-Writable Directories
Result: fail
Rule ID: root_path_no_groupother_writable
Time: 2014-10-07 12:26
Severity: low
For each element in root's path, run:
$ sudo ls -ld DIR
and ensure that write permissions are disabled for group and
other.
Such entries increase the risk that root could execute code provided by unprivileged users, and potentially malicious code.
Security identifiers
- CCE-26768-2
Result for Ensure that User Home Directories are not Group-Writable or World-Readable
Result: fail
Rule ID: homedir_perms_no_groupwrite_worldread
Time: 2014-10-07 12:26
Severity: low
For each human user of the system, view the permissions of the user's home directory:
$ sudo ls -ld /home/USER
Ensure that the directory is not group-writable and that it
is not world-readable. If necessary, repair the permissions:
$ sudo chmod g-w /home/USER
$ sudo chmod o-rwx /home/USER
This action may involve modifying user home directories. Notify your user community, and solicit input if appropriate, before making this type of change.
User home directories contain many configuration files which affect the behavior of a user's account. No user should ever have write permission to another user's home directory. Group shared directories can be configured in sub-directories or elsewhere in the filesystem if they are needed. Typically, user home directories should not be world-readable, as it would disclose file names to other users. If a subset of users need read access to one another's home directories, this can be provided using groups or ACLs.
Security identifiers
- CCE-26981-1
home directories
path | type | UID | GID | size | permissions |
/home/ | directory | 0 | 0 | 4096 | rwxr-xr-x |
Result for Ensure the Default Bash Umask is Set Correctly
Result: fixed
Rule ID: accounts_umask_bashrc
Time: 2014-10-07 12:28
Severity: low
To ensure the default umask for users of the Bash shell is set properly,
add or correct the umask
setting in /etc/bashrc
to read
as follows:
umask 077
The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.
Security identifiers
- CCE-26917-5
Remediation script
var_accounts_user_umask="077"
grep -q umask /etc/bashrc && \
sed -i "s/umask.*/umask $var_accounts_user_umask/g" /etc/bashrc
if ! [ $? -eq 0 ]; then
echo "umask $var_accounts_user_umask" >> /etc/bashrc
fi
Result for Ensure the Default C Shell Umask is Set Correctly
Result: fixed
Rule ID: accounts_umask_cshrc
Time: 2014-10-07 12:28
Severity: low
To ensure the default umask for users of the C shell is set properly,
add or correct the umask
setting in /etc/csh.cshrc
to read as follows:
umask 077
The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.
Security identifiers
- CCE-27034-8
Remediation script
var_accounts_user_umask="077"
grep -q umask /etc/csh.cshrc && \
sed -i "s/umask.*/umask $var_accounts_user_umask/g" /etc/csh.cshrc
if ! [ $? -eq 0 ]; then
echo "umask $var_accounts_user_umask" >> /etc/csh.cshrc
fi
Result for Ensure the Default Umask is Set Correctly in /etc/profile
Result: fixed
Rule ID: accounts_umask_etc_profile
Time: 2014-10-07 12:28
Severity: low
To ensure the default umask controlled by /etc/profile
is set properly,
add or correct the umask
setting in /etc/profile
to read as follows:
umask 077
The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.
Security identifiers
- CCE-26669-2
Remediation script
var_accounts_user_umask="077"
grep -q umask /etc/profile && \
sed -i "s/umask.*/umask $var_accounts_user_umask/g" /etc/profile
if ! [ $? -eq 0 ]; then
echo "umask $var_accounts_user_umask" >> /etc/profile
fi
Result for Ensure the Default Umask is Set Correctly in login.defs
Result: pass
Rule ID: accounts_umask_login_defs
Time: 2014-10-07 12:26
Severity: low
To ensure the default umask controlled by /etc/login.defs
is set properly,
add or correct the UMASK
setting in /etc/login.defs
to read as follows:
UMASK 077
The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read and written to by unauthorized users.
Security identifiers
- CCE-26371-5
Remediation script
var_accounts_user_umask="077"
grep -q UMASK /etc/login.defs && \
sed -i "s/UMASK.*/UMASK $var_accounts_user_umask/g" /etc/login.defs
if ! [ $? -eq 0 ]; then
echo "UMASK $var_accounts_user_umask" >> /etc/login.defs
fi
Result for Verify /etc/grub.conf User Ownership
Result: pass
Rule ID: user_owner_grub_conf
Time: 2014-10-07 12:26
Severity: medium
The file /etc/grub.conf
should
be owned by the root
user to prevent destruction
or modification of the file.
To properly set the owner of /etc/grub.conf
, run the command:
# chown root /etc/grub.conf
Only root should be able to modify important boot parameters.
Security identifiers
- CCE-26995-1
Result for Verify /etc/grub.conf Group Ownership
Result: pass
Rule ID: group_owner_grub_conf
Time: 2014-10-07 12:26
Severity: medium
The file /etc/grub.conf
should
be group-owned by the root
group to prevent
destruction or modification of the file.
To properly set the group owner of /etc/grub.conf
, run the command:
# chgrp root /etc/grub.conf
The root
group is a highly-privileged group. Furthermore, the group-owner of this
file should not have any access privileges anyway.
Security identifiers
- CCE-27022-3
Result for Verify /boot/grub/grub.conf Permissions
Result: pass
Rule ID: permissions_grub_conf
Time: 2014-10-07 12:26
Severity: medium
File permissions for /boot/grub/grub.conf
should be set to 600, which
is the default.
To properly set the permissions of /boot/grub/grub.conf
, run the command:
# chmod 600 /boot/grub/grub.conf
Proper permissions ensure that only the root user can modify important boot parameters.
Security identifiers
- CCE-26949-8
Result for Set Boot Loader Password
Result: fail
Rule ID: bootloader_password
Time: 2014-10-07 12:26
Severity: medium
The grub boot loader should have password protection enabled to protect boot-time settings. To do so, select a password and then generate a hash from it by running the following command:
$ grub-crypt --sha-512
When prompted to enter a password, insert the following line into /etc/grub.conf
immediately after the header comments. (Use the output from grub-crypt
as the
value of password-hash):
password --encrypted password-hash
NOTE: To meet FISMA Moderate, the bootloader password MUST differ from the root password.
Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.
Security identifiers
- CCE-26911-8
Result for Disable Interactive Boot
Result: fixed
Rule ID: disable_interactive_boot
Time: 2014-10-07 12:28
Severity: medium
To disable the ability for users to perform interactive startups,
edit the file /etc/sysconfig/init
.
Add or correct the line:
PROMPT=no
The PROMPT
option allows the console user to perform an
interactive system startup, in which it is possible to select the
set of services which are started on boot.
Using interactive boot, the console user could disable auditing, firewalls, or other services, weakening system security.
Security identifiers
- CCE-27043-9
Remediation script
grep -q ^PROMPT /etc/sysconfig/init && \
sed -i "s/PROMPT.*/PROMPT=no/g" /etc/sysconfig/init
if ! [ $? -eq 0 ]; then
echo "PROMPT=no" >> /etc/sysconfig/init
fi
Result for Set GNOME Login Inactivity Timeout
Result: fail
Rule ID: set_screensaver_inactivity_timeout
Time: 2014-10-07 12:26
Severity: medium
Run the following command to set the idle time-out value for inactivity in the GNOME desktop to 15 minutes:
$ sudo gconftool-2 \
--direct \
--config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
--type int \
--set /desktop/gnome/session/idle_delay 15
Setting the idle delay controls when the screensaver will start, and can be combined with screen locking to prevent access from passersby.
Security identifiers
- CCE-26828-4
Result for GNOME Desktop Screensaver Mandatory Use
Result: fail
Rule ID: enable_screensaver_after_idle
Time: 2014-10-07 12:26
Severity: medium
Run the following command to activate the screensaver in the GNOME desktop after a period of inactivity:
$ sudo gconftool-2 --direct \
--config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
--type bool \
--set /apps/gnome-screensaver/idle_activation_enabled true
Enabling idle activation of the screensaver ensures the screensaver will be activated after the idle delay. Applications requiring continuous, real-time screen display (such as network management products) require the login session does not have administrator rights and the display station is located in a controlled-access area.
Security identifiers
- CCE-26600-7
Result for Enable Screen Lock Activation After Idle Period
Result: fail
Rule ID: enable_screensaver_password_lock
Time: 2014-10-07 12:26
Severity: medium
Run the following command to activate locking of the screensaver in the GNOME desktop when it is activated:
$ sudo gconftool-2 --direct \
--config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
--type bool \
--set /apps/gnome-screensaver/lock_enabled true
Enabling the activation of the screen lock after an idle period ensures password entry will be required in order to access the system, preventing access by passersby.
Security identifiers
- CCE-26235-2
Result for Implement Blank Screensaver
Result: fail
Rule ID: set_blank_screensaver
Time: 2014-10-07 12:26
Severity: low
Run the following command to set the screensaver mode in the GNOME desktop to a blank screen:
$ sudo gconftool-2 --direct \
--config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
--type string \
--set /apps/gnome-screensaver/mode blank-only
Setting the screensaver mode to blank-only conceals the contents of the display from passersby.
Security identifiers
- CCE-26638-7
Result for Modify the System Login Banner
Result: fixed
Rule ID: set_system_login_banner
Time: 2014-10-07 12:28
Severity: medium
To configure the system login banner:
Edit /etc/issue
. Replace the default text with a message
compliant with the local site policy or a legal disclaimer.
The DoD required text is either:
You are accessing a U.S. Government (USG) Information System (IS) that is
provided for USG-authorized use only. By using this IS (which includes any
device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS for purposes
including, but not limited to, penetration testing, COMSEC monitoring, network
operations and defense, personnel misconduct (PM), law enforcement (LE), and
counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private, are subject
to routine monitoring, interception, and search, and may be disclosed or used
for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access controls)
to protect USG interests -- not for your personal benefit or privacy.
-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative
searching or monitoring of the content of privileged communications, or work
product, related to personal representation or services by attorneys,
psychotherapists, or clergy, and their assistants. Such communications and work
product are private and confidential. See User Agreement for details.
OR:
I've read & consent to terms in IS user agreem't.
An appropriate warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers.
Security identifiers
- CCE-26974-6
Remediation script
login_banner_text="
-- WARNING --[\s\n]*This system is for the use of authorized users only. Individuals[\s\n]*using this computer system without authority or in excess of their[\s\n]*authority are subject to having all their activities on this system[\s\n]*monitored and recorded by system personnel. Anyone using this[\s\n]*system expressly consents to such monitoring and is advised that[\s\n]*if such monitoring reveals possible evidence of criminal activity[\s\n]*system personal may provide the evidence of such monitoring to law[\s\n]*enforcement officials."
# There was a regular-expression matching various banners, needs to be expanded
expanded=$(echo "$login_banner_text" | sed 's/\[\\s\\n\][*+]/ /g;s/\\//g;')
cat <<EOF >/etc/issue
$expanded
EOF
Result for Enable GUI Warning Banner
Result: fail
Rule ID: enable_gdm_login_banner
Time: 2014-10-07 12:27
Severity: medium
To enable displaying a login warning banner in the GNOME Display Manager's login screen, run the following command:
$ sudo gconftool-2 --direct \
--config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
--type bool \
--set /apps/gdm/simple-greeter/banner_message_enable true
To display a banner, this setting must be enabled and then
banner text must also be set.
An appropriate warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers.
Security identifiers
- CCE-27195-7
Result for Disable Zeroconf Networking
Result: fixed
Rule ID: network_disable_zeroconf
Time: 2014-10-07 12:28
Severity: low
Zeroconf networking allows the system to assign itself an IP
address and engage in IP communication without a statically-assigned address or
even a DHCP server. Automatic address assignment via Zeroconf (or DHCP) is not
recommended. To disable Zeroconf automatic route assignment in the 169.254.0.0
subnet, add or correct the following line in /etc/sysconfig/network
:
NOZEROCONF=yes
Zeroconf addresses are in the network 169.254.0.0. The networking scripts add entries to the system's routing table for these addresses. Zeroconf address assignment commonly occurs when the system is configured to use DHCP but fails to receive an address assignment from the DHCP server.
Security identifiers
- CCE-27151-0
Remediation script
echo "NOZEROCONF=yes" >> /etc/sysconfig/network
Result for Disable Kernel Parameter for Sending ICMP Redirects by Default
Result: error
Rule ID: sysctl_net_ipv4_conf_default_send_redirects
Time: 2014-10-07 12:28
Severity: medium
To set the runtime status of the net.ipv4.conf.default.send_redirects
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.default.send_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.default.send_redirects = 0
Sending ICMP redirects permits the system to instruct other systems to update their routing information. The ability to send ICMP redirects is only appropriate for systems acting as routers.
Security identifiers
- CCE-27001-7
Remediation script
#
# Set runtime for net.ipv4.conf.default.send_redirects
#
sysctl -q -n -w net.ipv4.conf.default.send_redirects=0
#
# If net.ipv4.conf.default.send_redirects present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.default.send_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.send_redirects /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.default.send_redirects.*/net.ipv4.conf.default.send_redirects = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.default.send_redirects to 0 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.default.send_redirects = 0" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv4.conf.default.send_redirects set to 0
name | value |
net.ipv4.conf.default.send_redirects | 1 |
Result for Disable Kernel Parameter for Sending ICMP Redirects for All Interfaces
Result: error
Rule ID: sysctl_net_ipv4_conf_all_send_redirects
Time: 2014-10-07 12:28
Severity: medium
To set the runtime status of the net.ipv4.conf.all.send_redirects
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.all.send_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.all.send_redirects = 0
Sending ICMP redirects permits the system to instruct other systems to update their routing information. The ability to send ICMP redirects is only appropriate for systems acting as routers.
Security identifiers
- CCE-27004-1
Remediation script
#
# Set runtime for net.ipv4.conf.all.send_redirects
#
sysctl -q -n -w net.ipv4.conf.all.send_redirects=0
#
# If net.ipv4.conf.all.send_redirects present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.all.send_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.send_redirects /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.all.send_redirects.*/net.ipv4.conf.all.send_redirects = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.all.send_redirects to 0 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.all.send_redirects = 0" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv4.conf.all.send_redirects set to 0
name | value |
net.ipv4.conf.all.send_redirects | 1 |
Result for Disable Kernel Parameter for IP Forwarding
Result: pass
Rule ID: sysctl_ipv4_ip_forward
Time: 2014-10-07 12:27
Severity: medium
To set the runtime status of the net.ipv4.ip_forward
kernel parameter,
run the following command:
# sysctl -w net.ipv4.ip_forward=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.ip_forward = 0
IP forwarding permits the kernel to forward packets from one network interface to another. The ability to forward packets between two networks is only appropriate for systems acting as routers.
Security identifiers
- CCE-26866-4
Result for Disable Kernel Parameter for Accepting ICMP Redirects for All Interfaces
Result: error
Rule ID: sysctl_net_ipv4_conf_all_accept_redirects
Time: 2014-10-07 12:28
Severity: medium
To set the runtime status of the net.ipv4.conf.all.accept_redirects
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.all.accept_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.all.accept_redirects = 0
Accepting ICMP redirects has few legitimate uses. It should be disabled unless it is absolutely required.
Security identifiers
- CCE-27027-2
Remediation script
#
# Set runtime for net.ipv4.conf.all.accept_redirects
#
sysctl -q -n -w net.ipv4.conf.all.accept_redirects=0
#
# If net.ipv4.conf.all.accept_redirects present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.all.accept_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.accept_redirects /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.all.accept_redirects.*/net.ipv4.conf.all.accept_redirects = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.all.accept_redirects to 0 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.all.accept_redirects = 0" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv4.conf.all.accept_redirects set to 0
name | value |
net.ipv4.conf.all.accept_redirects | 1 |
Result for Disable Kernel Parameter for Accepting Secure Redirects for All Interfaces
Result: error
Rule ID: sysctl_net_ipv4_conf_all_secure_redirects
Time: 2014-10-07 12:28
Severity: medium
To set the runtime status of the net.ipv4.conf.all.secure_redirects
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.all.secure_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.all.secure_redirects = 0
Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
Security identifiers
- CCE-26854-0
Remediation script
#
# Set runtime for net.ipv4.conf.all.secure_redirects
#
sysctl -q -n -w net.ipv4.conf.all.secure_redirects=0
#
# If net.ipv4.conf.all.secure_redirects present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.all.secure_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.secure_redirects /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.all.secure_redirects.*/net.ipv4.conf.all.secure_redirects = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.all.secure_redirects to 0 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.all.secure_redirects = 0" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv4.conf.all.secure_redirects set to 0
name | value |
net.ipv4.conf.all.secure_redirects | 1 |
Result for Enable Kernel Parameter to Log Martian Packets
Result: error
Rule ID: sysctl_net_ipv4_conf_all_log_martians
Time: 2014-10-07 12:28
Severity: low
To set the runtime status of the net.ipv4.conf.all.log_martians
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.all.log_martians=1
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.all.log_martians = 1
The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
Security identifiers
- CCE-27066-0
Remediation script
#
# Set runtime for net.ipv4.conf.all.log_martians
#
sysctl -q -n -w net.ipv4.conf.all.log_martians=1
#
# If net.ipv4.conf.all.log_martians present in /etc/sysctl.conf, change value to "1"
# else, add "net.ipv4.conf.all.log_martians = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.log_martians /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.all.log_martians.*/net.ipv4.conf.all.log_martians = 1/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.all.log_martians to 1 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.all.log_martians = 1" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv4.conf.all.log_martians set to 1
name | value |
net.ipv4.conf.all.log_martians | 0 |
Result for Disable Kernel Parameter for Accepting Source-Routed Packets By Default
Result: pass
Rule ID: sysctl_net_ipv4_conf_default_accept_source_route
Time: 2014-10-07 12:27
Severity: medium
To set the runtime status of the net.ipv4.conf.default.accept_source_route
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.default.accept_source_route=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.default.accept_source_route = 0
Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Security identifiers
- CCE-26983-7
Remediation script
#
# Set runtime for net.ipv4.conf.default.accept_source_route
#
sysctl -q -n -w net.ipv4.conf.default.accept_source_route=0
#
# If net.ipv4.conf.default.accept_source_route present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.default.accept_source_route = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.accept_source_route /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.default.accept_source_route.*/net.ipv4.conf.default.accept_source_route = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.default.accept_source_route to 0 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.default.accept_source_route = 0" >> /etc/sysctl.conf
fi
Result for Disable Kernel Parameter for Accepting ICMP Redirects By Default
Result: error
Rule ID: sysctl_net_ipv4_conf_default_accept_redirects
Time: 2014-10-07 12:28
Severity: low
To set the runtime status of the net.ipv4.conf.default.accept_redirects
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.default.accept_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.default.accept_redirects = 0
This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Security identifiers
- CCE-27015-7
Remediation script
#
# Set runtime for net.ipv4.conf.default.accept_redirects
#
sysctl -q -n -w net.ipv4.conf.default.accept_redirects=0
#
# If net.ipv4.conf.default.accept_redirects present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.default.accept_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.accept_redirects /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.default.accept_redirects.*/net.ipv4.conf.default.accept_redirects = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.default.accept_redirects to 0 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.default.accept_redirects = 0" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv4.conf.default.accept_redirects set to 0
name | value |
net.ipv4.conf.default.accept_redirects | 1 |
Result for Disable Kernel Parameter for Accepting Secure Redirects By Default
Result: error
Rule ID: sysctl_net_ipv4_conf_default_secure_redirects
Time: 2014-10-07 12:28
Severity: medium
To set the runtime status of the net.ipv4.conf.default.secure_redirects
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.default.secure_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.default.secure_redirects = 0
Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
Security identifiers
- CCE-26831-8
Remediation script
#
# Set runtime for net.ipv4.conf.default.secure_redirects
#
sysctl -q -n -w net.ipv4.conf.default.secure_redirects=0
#
# If net.ipv4.conf.default.secure_redirects present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv4.conf.default.secure_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.secure_redirects /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.default.secure_redirects.*/net.ipv4.conf.default.secure_redirects = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.default.secure_redirects to 0 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.default.secure_redirects = 0" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv4.conf.default.secure_redirects set to 0
name | value |
net.ipv4.conf.default.secure_redirects | 1 |
Result for Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests
Result: fixed
Rule ID: sysctl_net_ipv4_icmp_echo_ignore_broadcasts
Time: 2014-10-07 12:28
Severity: low
To set the runtime status of the net.ipv4.icmp_echo_ignore_broadcasts
kernel parameter,
run the following command:
# sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.icmp_echo_ignore_broadcasts = 1
Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.
Security identifiers
- CCE-26883-9
Remediation script
#
# Set runtime for net.ipv4.icmp_echo_ignore_broadcasts
#
sysctl -q -n -w net.ipv4.icmp_echo_ignore_broadcasts=1
#
# If net.ipv4.icmp_echo_ignore_broadcasts present in /etc/sysctl.conf, change value to "1"
# else, add "net.ipv4.icmp_echo_ignore_broadcasts = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.icmp_echo_ignore_broadcasts /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.icmp_echo_ignore_broadcasts.*/net.ipv4.icmp_echo_ignore_broadcasts = 1/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.icmp_echo_ignore_broadcasts to 1 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.icmp_echo_ignore_broadcasts = 1" >> /etc/sysctl.conf
fi
Result for Enable Kernel Parameter to Ignore Bogus ICMP Error Responses
Result: fixed
Rule ID: sysctl_net_ipv4_icmp_ignore_bogus_error_responses
Time: 2014-10-07 12:28
Severity: low
To set the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses
kernel parameter,
run the following command:
# sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.icmp_ignore_bogus_error_responses = 1
Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.
Security identifiers
- CCE-26993-6
Remediation script
#
# Set runtime for net.ipv4.icmp_ignore_bogus_error_responses
#
sysctl -q -n -w net.ipv4.icmp_ignore_bogus_error_responses=1
#
# If net.ipv4.icmp_ignore_bogus_error_responses present in /etc/sysctl.conf, change value to "1"
# else, add "net.ipv4.icmp_ignore_bogus_error_responses = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.icmp_ignore_bogus_error_responses /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.icmp_ignore_bogus_error_responses.*/net.ipv4.icmp_ignore_bogus_error_responses = 1/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.icmp_ignore_bogus_error_responses to 1 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.icmp_ignore_bogus_error_responses = 1" >> /etc/sysctl.conf
fi
Result for Enable Kernel Parameter to Use TCP Syncookies
Result: pass
Rule ID: sysctl_net_ipv4_tcp_syncookies
Time: 2014-10-07 12:27
Severity: medium
To set the runtime status of the net.ipv4.tcp_syncookies
kernel parameter,
run the following command:
# sysctl -w net.ipv4.tcp_syncookies=1
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.tcp_syncookies = 1
A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests.
Security identifiers
- CCE-27053-8
Remediation script
#
# Set runtime for net.ipv4.tcp_syncookies
#
sysctl -q -n -w net.ipv4.tcp_syncookies=1
#
# If net.ipv4.tcp_syncookies present in /etc/sysctl.conf, change value to "1"
# else, add "net.ipv4.tcp_syncookies = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.tcp_syncookies /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.tcp_syncookies.*/net.ipv4.tcp_syncookies = 1/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.tcp_syncookies to 1 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.tcp_syncookies = 1" >> /etc/sysctl.conf
fi
Result for Enable Kernel Parameter to Use Reverse Path Filtering for All Interfaces
Result: error
Rule ID: sysctl_net_ipv4_conf_all_rp_filter
Time: 2014-10-07 12:28
Severity: medium
To set the runtime status of the net.ipv4.conf.all.rp_filter
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.all.rp_filter=1
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.all.rp_filter = 1
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
Security identifiers
- CCE-26979-5
Remediation script
#
# Set runtime for net.ipv4.conf.all.rp_filter
#
sysctl -q -n -w net.ipv4.conf.all.rp_filter=1
#
# If net.ipv4.conf.all.rp_filter present in /etc/sysctl.conf, change value to "1"
# else, add "net.ipv4.conf.all.rp_filter = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.all.rp_filter /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.all.rp_filter.*/net.ipv4.conf.all.rp_filter = 1/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.all.rp_filter to 1 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.all.rp_filter = 1" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv4.conf.all.rp_filter set to 1
name | value |
net.ipv4.conf.all.rp_filter | 0 |
Result for Enable Kernel Parameter to Use Reverse Path Filtering by Default
Result: pass
Rule ID: sysctl_net_ipv4_conf_default_rp_filter
Time: 2014-10-07 12:27
Severity: medium
To set the runtime status of the net.ipv4.conf.default.rp_filter
kernel parameter,
run the following command:
# sysctl -w net.ipv4.conf.default.rp_filter=1
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv4.conf.default.rp_filter = 1
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
Security identifiers
- CCE-26915-9
Remediation script
#
# Set runtime for net.ipv4.conf.default.rp_filter
#
sysctl -q -n -w net.ipv4.conf.default.rp_filter=1
#
# If net.ipv4.conf.default.rp_filter present in /etc/sysctl.conf, change value to "1"
# else, add "net.ipv4.conf.default.rp_filter = 1" to /etc/sysctl.conf
#
if grep --silent ^net.ipv4.conf.default.rp_filter /etc/sysctl.conf ; then
sed -i 's/^net.ipv4.conf.default.rp_filter.*/net.ipv4.conf.default.rp_filter = 1/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv4.conf.default.rp_filter to 1 per security requirements" >> /etc/sysctl.conf
echo "net.ipv4.conf.default.rp_filter = 1" >> /etc/sysctl.conf
fi
Result for Disable WiFi or Bluetooth in BIOS
Result: notchecked
Rule ID: wireless_disable_in_bios
Time: 2014-10-07 12:27
Severity: low
Some systems that include built-in wireless support offer the ability to disable the device through the BIOS. This is system-specific; consult your hardware manual or explore the BIOS setup during boot.
Disabling wireless support in the BIOS prevents easy activation of the wireless interface, generally requiring administrators to reboot the system first.
Security identifiers
- CCE-26878-9
Result for Deactivate Wireless Network Interfaces
Result: pass
Rule ID: deactivate_wireless_interfaces
Time: 2014-10-07 12:27
Severity: low
Deactivating wireless network interfaces should prevent
normal usage of the wireless capability.
First, identify the interfaces available with the command:
$ ifconfig -a
Additionally, the following command may be used to
determine whether wireless support is included for a
particular interface, though this may not always be a clear
indicator:
$ iwconfig
After identifying any wireless interfaces (which may have
names like wlan0
, ath0
, wifi0
, em1
or
eth0
), deactivate the interface with the command:
$ sudo ifdown interface
These changes will only last until the next reboot. To
disable the interface for future boots, remove the appropriate
interface file from /etc/sysconfig/network-scripts
:
$ sudo rm /etc/sysconfig/network-scripts/ifcfg-interface
Wireless networking allows attackers within physical proximity to launch network-based attacks against systems, including those against local LAN protocols which were not designed with security in mind.
Security identifiers
- CCE-27057-9
Result for Disable Bluetooth Service
Result: pass
Rule ID: service_bluetooth_disabled
Time: 2014-10-07 12:27
Severity: medium
The bluetooth
service can be disabled with the following command:
# chkconfig bluetooth off
$ sudo service bluetooth stop
Disabling the bluetooth
service prevents the system from attempting
connections to Bluetooth devices, which entails some security risk.
Nevertheless, variation in this risk decision may be expected due to the
utility of Bluetooth connectivity and its limited range.
Security identifiers
- CCE-27081-9
Remediation script
#
# Disable bluetooth for all run levels
#
chkconfig --level 0123456 bluetooth off
#
# Stop bluetooth if currently running
#
service bluetooth stop
Result for Disable Bluetooth Kernel Modules
Result: fail
Rule ID: kernel_module_bluetooth_disabled
Time: 2014-10-07 12:27
Severity: medium
The kernel's module loading system can be configured to prevent
loading of the Bluetooth module. Add the following to
the appropriate /etc/modprobe.d
configuration file
to prevent the loading of the Bluetooth module:
install net-pf-31 /bin/false
install bluetooth /bin/false
If Bluetooth functionality must be disabled, preventing the kernel from loading the kernel module provides an additional safeguard against its activation.
Security identifiers
- CCE-26763-3
Result for Disable IPv6 Networking Support Automatic Loading
Result: fail
Rule ID: kernel_module_ipv6_option_disabled
Time: 2014-10-07 12:27
Severity: medium
To prevent the IPv6 kernel module (ipv6
) from loading the
IPv6 networking stack, add the following line to
/etc/modprobe.d/disabled.conf
(or another file in
/etc/modprobe.d
):
options ipv6 disable=1
This permits the IPv6 module to be loaded (and thus satisfy other modules that
depend on it), while disabling support for the IPv6 protocol.
Any unnecessary network stacks - including IPv6 - should be disabled, to reduce the vulnerability to exploitation.
Security identifiers
- CCE-27153-6
Result for Disable Support for RPC IPv6
Result: fail
Rule ID: network_ipv6_disable_rpc
Time: 2014-10-07 12:27
Severity: low
RPC services for NFSv4 try to load transport modules for
udp6
and tcp6
by default, even if IPv6 has been disabled in
/etc/modprobe.d
. To prevent RPC services such as rpc.mountd
from attempting to start IPv6 network listeners, remove or comment out the
following two lines in /etc/netconfig
:
udp6 tpi_clts v inet6 udp - -
tcp6 tpi_cots_ord v inet6 tcp - -
Security identifiers
- CCE-27232-8
Test for udp6 based rpc services
path | content |
/etc/netconfig | udp6 tpi_clts v inet6 udp - - |
Test for tcp6 based rpc services
path | content |
/etc/netconfig | tcp6 tpi_cots_ord v inet6 tcp - - |
Result for Disable Accepting IPv6 Router Advertisements
Result: error
Rule ID: sysctl_net_ipv6_conf_default_accept_ra
Time: 2014-10-07 12:28
Severity: low
To set the runtime status of the net.ipv6.conf.default.accept_ra
kernel parameter,
run the following command:
# sysctl -w net.ipv6.conf.default.accept_ra=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv6.conf.default.accept_ra = 0
An illicit router advertisement message could result in a man-in-the-middle attack.
Security identifiers
- CCE-27164-3
Remediation script
#
# Set runtime for net.ipv6.conf.default.accept_ra
#
sysctl -q -n -w net.ipv6.conf.default.accept_ra=0
#
# If net.ipv6.conf.default.accept_ra present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv6.conf.default.accept_ra = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv6.conf.default.accept_ra /etc/sysctl.conf ; then
sed -i 's/^net.ipv6.conf.default.accept_ra.*/net.ipv6.conf.default.accept_ra = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv6.conf.default.accept_ra to 0 per security requirements" >> /etc/sysctl.conf
echo "net.ipv6.conf.default.accept_ra = 0" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv6.conf.default.accept_ra set to 0
name | value |
net.ipv6.conf.default.accept_ra | 1 |
Result for Disable Accepting IPv6 Redirects
Result: error
Rule ID: sysctl_net_ipv6_conf_default_accept_redirects
Time: 2014-10-07 12:28
Severity: medium
To set the runtime status of the net.ipv6.conf.default.accept_redirects
kernel parameter,
run the following command:
# sysctl -w net.ipv6.conf.default.accept_redirects=0
If this is not the system's default value, add the following line to /etc/sysctl.conf
:
net.ipv6.conf.default.accept_redirects = 0
An illicit ICMP redirect message could result in a man-in-the-middle attack.
Security identifiers
- CCE-27166-8
Remediation script
#
# Set runtime for net.ipv6.conf.default.accept_redirects
#
sysctl -q -n -w net.ipv6.conf.default.accept_redirects=0
#
# If net.ipv6.conf.default.accept_redirects present in /etc/sysctl.conf, change value to "0"
# else, add "net.ipv6.conf.default.accept_redirects = 0" to /etc/sysctl.conf
#
if grep --silent ^net.ipv6.conf.default.accept_redirects /etc/sysctl.conf ; then
sed -i 's/^net.ipv6.conf.default.accept_redirects.*/net.ipv6.conf.default.accept_redirects = 0/g' /etc/sysctl.conf
else
echo "" >> /etc/sysctl.conf
echo "# Set net.ipv6.conf.default.accept_redirects to 0 per security requirements" >> /etc/sysctl.conf
echo "net.ipv6.conf.default.accept_redirects = 0" >> /etc/sysctl.conf
fi
kernel runtime parameter net.ipv6.conf.default.accept_redirects set to 0
name | value |
net.ipv6.conf.default.accept_redirects | 1 |
Result for Verify ip6tables Enabled if Using IPv6
Result: pass
Rule ID: service_ip6tables_enabled
Time: 2014-10-07 12:27
Severity: medium
The ip6tables
service can be enabled with the following command:
# chkconfig --level 2345 ip6tables on
The ip6tables
service provides the system's host-based firewalling
capability for IPv6 and ICMPv6.
Security identifiers
- CCE-27006-6
Remediation script
#
# Enable ip6tables for all run levels
#
chkconfig --level 0123456 ip6tables on
#
# Start ip6tables if not currently running
#
service ip6tables start
Result for Verify iptables Enabled
Result: pass
Rule ID: service_iptables_enabled
Time: 2014-10-07 12:27
Severity: medium
The iptables
service can be enabled with the following command:
# chkconfig --level 2345 iptables on
The iptables
service provides the system's host-based firewalling
capability for IPv4 and ICMP.
Security identifiers
- CCE-27018-1
Remediation script
#
# Enable iptables for all run levels
#
chkconfig --level 0123456 iptables on
#
# Start iptables if not currently running
#
service iptables start
Result for Set Default iptables Policy for Incoming Packets
Result: fixed
Rule ID: set_iptables_default_rule
Time: 2014-10-07 12:28
Severity: medium
To set the default policy to DROP (instead of ACCEPT) for
the built-in INPUT chain which processes incoming packets,
add or correct the following line in
/etc/sysconfig/iptables
:
:INPUT DROP [0:0]
In iptables
the default policy is applied only after all
the applicable rules in the table are examined for a match. Setting the
default policy to DROP
implements proper design for a firewall, i.e.
any packets which are not explicitly permitted should not be
accepted.
Security identifiers
- CCE-26444-0
Remediation script
sed -i 's/^:INPUT ACCEPT.*/:INPUT DROP [0:0]/g' /etc/sysconfig/iptables
Result for Set Default iptables Policy for Forwarded Packets
Result: fixed
Rule ID: set_iptables_default_rule_forward
Time: 2014-10-07 12:28
Severity: medium
To set the default policy to DROP (instead of ACCEPT) for
the built-in FORWARD chain which processes packets that will be forwarded from
one interface to another,
add or correct the following line in
/etc/sysconfig/iptables
:
:FORWARD DROP [0:0]
In iptables
, the default policy is applied only after all
the applicable rules in the table are examined for a match. Setting the
default policy to DROP
implements proper design for a firewall, i.e.
any packets which are not explicitly permitted should not be
accepted.
Security identifiers
- CCE-27186-6
Remediation script
sed -i 's/^:FORWARD ACCEPT.*/:FORWARD DROP [0:0]/g' /etc/sysconfig/iptables
Result for Disable DCCP Support
Result: fixed
Rule ID: kernel_module_dccp_disabled
Time: 2014-10-07 12:28
Severity: medium
The Datagram Congestion Control Protocol (DCCP) is a
relatively new transport layer protocol, designed to support
streaming media and telephony.
To configure the system to prevent the dccp
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install dccp /bin/false
Disabling DCCP protects the system against exploitation of any flaws in its implementation.
Security identifiers
- CCE-26448-1
Remediation script
echo "install dccp /bin/false" > /etc/modprobe.d/dccp.conf
Result for Disable SCTP Support
Result: fixed
Rule ID: kernel_module_sctp_disabled
Time: 2014-10-07 12:28
Severity: medium
The Stream Control Transmission Protocol (SCTP) is a
transport layer protocol, designed to support the idea of
message-oriented communication, with several streams of messages
within one connection.
To configure the system to prevent the sctp
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install sctp /bin/false
Disabling SCTP protects the system against exploitation of any flaws in its implementation.
Security identifiers
- CCE-26410-1
Remediation script
echo "install sctp /bin/false" > /etc/modprobe.d/sctp.conf
Result for Disable RDS Support
Result: fixed
Rule ID: kernel_module_rds_disabled
Time: 2014-10-07 12:28
Severity: low
The Reliable Datagram Sockets (RDS) protocol is a transport
layer protocol designed to provide reliable high- bandwidth,
low-latency communications between nodes in a cluster.
To configure the system to prevent the rds
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install rds /bin/false
Disabling RDS protects the system against exploitation of any flaws in its implementation.
Security identifiers
- CCE-26239-4
Remediation script
echo "install rds /bin/false" > /etc/modprobe.d/rds.conf
Result for Disable TIPC Support
Result: fixed
Rule ID: kernel_module_tipc_disabled
Time: 2014-10-07 12:28
Severity: medium
The Transparent Inter-Process Communication (TIPC) protocol
is designed to provide communications between nodes in a
cluster.
To configure the system to prevent the tipc
kernel module from being loaded, add the following line to a file in the directory /etc/modprobe.d
:
install tipc /bin/false
Disabling TIPC protects the system against exploitation of any flaws in its implementation.
Security identifiers
- CCE-26696-5
Remediation script
echo "install tipc /bin/false" > /etc/modprobe.d/tipc.conf
Result for Ensure rsyslog is Installed
Result: pass
Rule ID: package_rsyslog_installed
Time: 2014-10-07 12:27
Severity: medium
Rsyslog is installed by default.
The rsyslog
package can be installed with the following command:
# yum install rsyslog
The rsyslog package provides the rsyslog daemon, which provides system logging services.
Security identifiers
- CCE-26809-4
Remediation script
yum -y install rsyslog
Result for Enable rsyslog Service
Result: pass
Rule ID: service_rsyslog_enabled
Time: 2014-10-07 12:27
Severity: medium
The rsyslog
service provides syslog-style logging by default on RHEL 6.
The rsyslog
service can be enabled with the following command:
# chkconfig --level 2345 rsyslog on
The rsyslog
service must be running in order to provide
logging services, which are essential to system administration.
Security identifiers
- CCE-26807-8
Remediation script
#
# Enable rsyslog for all run levels
#
chkconfig --level 0123456 rsyslog on
#
# Start rsyslog if not currently running
#
service rsyslog start
Result for Ensure Log Files Are Owned By Appropriate User
Result: fail
Rule ID: userowner_rsyslog_files
Time: 2014-10-07 12:27
Severity: medium
The owner of all log files written by
rsyslog
should be root.
These log files are determined by the second part of each Rule line in
/etc/rsyslog.conf
and typically all appear in /var/log
.
For each log file LOGFILE referenced in /etc/rsyslog.conf
,
run the following command to inspect the file's owner:
$ ls -l LOGFILE
If the owner is not root
, run the following command to
correct this:
$ sudo chown root LOGFILE
The log files generated by rsyslog contain valuable information regarding system configuration, user authentication, and other such information. Log files should be protected from unauthorized access.
Security identifiers
- CCE-26812-8
Files that end in .log in /var/log owned by root
path | type | UID | GID | size | permissions |
/var/log/mysqld.log | regular | 27 | 27 | 0 | rw-r-----Â |
Result for Ensure Log Files Are Owned By Appropriate Group
Result: unknown
Rule ID: groupowner_rsyslog_files
Time: 2014-10-07 12:27
Severity: medium
The group-owner of all log files written by
rsyslog
should be root.
These log files are determined by the second part of each Rule line in
/etc/rsyslog.conf
and typically all appear in /var/log
.
For each log file LOGFILE referenced in /etc/rsyslog.conf
,
run the following command to inspect the file's group owner:
$ ls -l LOGFILE
If the owner is not root
, run the following command to
correct this:
$ sudo chgrp root LOGFILE
The log files generated by rsyslog contain valuable information regarding system configuration, user authentication, and other such information. Log files should be protected from unauthorized access.
Security identifiers
- CCE-26821-9
Result for Ensure System Log Files Have Correct Permissions
Result: unknown
Rule ID: rsyslog_file_permissions
Time: 2014-10-07 12:27
Severity: medium
The file permissions for all log files written by
rsyslog
should be set to 600, or more restrictive.
These log files are determined by the second part of each Rule line in
/etc/rsyslog.conf
and typically all appear in /var/log
.
For each log file LOGFILE referenced in /etc/rsyslog.conf
,
run the following command to inspect the file's permissions:
$ ls -l LOGFILE
If the permissions are not 600 or more restrictive,
run the following command to correct this:
$ sudo chmod 0600 LOGFILE
Log files can contain valuable information regarding system configuration. If the system log files are not protected unauthorized users could change the logged data, eliminating their forensic value.
Security identifiers
- CCE-27190-8
Result for Ensure Logs Sent To Remote Host
Result: fail
Rule ID: rsyslog_send_messages_to_logserver
Time: 2014-10-07 12:27
Severity: low
To configure rsyslog to send logs to a remote log server,
open /etc/rsyslog.conf
and read and understand the last section of the file,
which describes the multiple directives necessary to activate remote
logging.
Along with these other directives, the system can be configured
to forward its logs to a particular log server by
adding or correcting one of the following lines,
substituting loghost.example.com
appropriately.
The choice of protocol depends on the environment of the system;
although TCP and RELP provide more reliable message delivery,
they may not be supported in all environments.
To use UDP for log message delivery:
*.* @loghost.example.com
To use TCP for log message delivery:
*.* @@loghost.example.com
To use RELP for log message delivery:
*.* :omrelp:loghost.example.com
A log server (loghost) receives syslog messages from one or more systems. This data can be used as an additional log source in the event a system is compromised and its local logs are suspect. Forwarding log messages to a remote loghost also provides system administrators with a centralized place to view the status of multiple hosts within the enterprise.
Security identifiers
- CCE-26801-1
Result for Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
Result: pass
Rule ID: rsyslog_accept_remote_messages_none
Time: 2014-10-07 12:27
Severity: low
The rsyslog
daemon should not accept remote messages
unless the system acts as a log server.
To ensure that it is not listening on the network, ensure the following lines are
not found in /etc/rsyslog.conf
:
$ModLoad imtcp
$InputTCPServerRun port
$ModLoad imudp
$UDPServerRun port
$ModLoad imrelp
$InputRELPServerRun port
Any process which receives messages from the network incurs some risk of receiving malicious messages. This risk can be eliminated for rsyslog by configuring it not to listen on the network.
Security identifiers
- CCE-26803-7
Result for Ensure Logrotate Runs Periodically
Result: pass
Rule ID: ensure_logrotate_activated
Time: 2014-10-07 12:27
Severity: low
The logrotate
utility allows for the automatic rotation of
log files. The frequency of rotation is specified in /etc/logrotate.conf
,
which triggers a cron task. To configure logrotate to run daily, add or correct
the following line in /etc/logrotate.conf
:
# rotate log files frequency
daily
Log files that are not properly rotated run the risk of growing so large that they fill up the /var/log partition. Valuable logging information could be lost if the /var/log partition becomes full.
Security identifiers
- CCE-27014-0
Result for Enable auditd Service
Result: pass
Rule ID: service_auditd_enabled
Time: 2014-10-07 12:27
Severity: medium
The auditd
service is an essential userspace component of
the Linux Auditing System, as it is responsible for writing audit records to
disk.
The auditd
service can be enabled with the following command:
# chkconfig --level 2345 auditd on
Ensuring the auditd
service is active ensures
audit records generated by the kernel can be written to disk, or that appropriate
actions will be taken if other obstacles exist.
Security identifiers
- CCE-27058-7
Remediation script
#
# Enable auditd for all run levels
#
chkconfig --level 0123456 auditd on
#
# Start auditd if not currently running
#
service auditd start
Result for Enable Auditing for Processes Which Start Prior to the Audit Daemon
Result: fixed
Rule ID: bootloader_audit_argument
Time: 2014-10-07 12:28
Severity: medium
To ensure all processes can be audited, even
those which start prior to the audit daemon, add the argument
audit=1
to the kernel line in /etc/grub.conf
, in the manner below:
kernel /vmlinuz-version ro vga=ext root=/dev/VolGroup00/LogVol00 rhgb quiet audit=1
Each process on the system carries an "auditable" flag which
indicates whether its activities can be audited. Although auditd
takes care of enabling this for all processes which launch after it
does, adding the kernel argument ensures it is set for every
process during boot.
Security identifiers
- CCE-26785-6
Remediation script
/sbin/grubby --update-kernel=ALL --args="audit=1"
Result for Record attempts to alter time through adjtimex
Result: fail
Rule ID: audit_rules_time_adjtimex
Time: 2014-10-07 12:27
Severity: low
On a 32-bit system, add the following to /etc/audit/audit.rules
:
# audit_time_rules
-a always,exit -F arch=b32 -S adjtimex -k audit_time_rules
On a 64-bit system, add the following to /etc/audit/audit.rules
:
# audit_time_rules
-a always,exit -F arch=b64 -S adjtimex -k audit_time_rules
The -k option allows for the specification of a key in string form that can
be used for better reporting capability through ausearch and aureport.
Multiple system calls can be defined on the same line to save space if
desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex -S settimeofday -S clock_settime
-k audit_time_rules
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Security identifiers
- CCE-26242-8
Result for Record attempts to alter time through settimeofday
Result: fail
Rule ID: audit_rules_time_settimeofday
Time: 2014-10-07 12:27
Severity: low
On a 32-bit system, add the following to /etc/audit/audit.rules
:
# audit_time_rules
-a always,exit -F arch=b32 -S settimeofday -k audit_time_rules
On a 64-bit system, add the following to /etc/audit/audit.rules
:
# audit_time_rules
-a always,exit -F arch=b64 -S settimeofday -k audit_time_rules
The -k option allows for the specification of a key in string form that can
be used for better reporting capability through ausearch and aureport.
Multiple system calls can be defined on the same line to save space if
desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex -S settimeofday -S clock_settime
-k audit_time_rules
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Security identifiers
- CCE-27203-9
Result for Record Attempts to Alter Time Through stime
Result: fail
Rule ID: audit_rules_time_stime
Time: 2014-10-07 12:27
Severity: low
On a 32-bit system, add the following to /etc/audit/audit.rules
:
# audit_time_rules
-a always,exit -F arch=b32 -S stime -k audit_time_rules
On a 64-bit system, the "-S stime" is not necessary. The -k option allows for
the specification of a key in string form that can be used for better
reporting capability through ausearch and aureport. Multiple system calls
can be defined on the same line to save space if desired, but is not required.
See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex -S settimeofday -S clock_settime
-k audit_time_rules
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Security identifiers
- CCE-27169-2
Result for Record Attempts to Alter Time Through clock_settime
Result: fail
Rule ID: audit_rules_time_clock_settime
Time: 2014-10-07 12:27
Severity: low
On a 32-bit system, add the following to /etc/audit/audit.rules
:
# audit_time_rules
-a always,exit -F arch=b32 -S clock_settime -k audit_time_rules
On a 64-bit system, add the following to /etc/audit/audit.rules
:
# audit_time_rules
-a always,exit -F arch=b64 -S clock_settime -k audit_time_rules
The -k option allows for the specification of a key in string form that can
be used for better reporting capability through ausearch and aureport.
Multiple system calls can be defined on the same line to save space if
desired, but is not required. See an example of multiple combined syscalls:
-a always,exit -F arch=b64 -S adjtimex -S settimeofday -S clock_settime
-k audit_time_rules
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Security identifiers
- CCE-27170-0
Result for Record Attempts to Alter the localtime File
Result: fail
Rule ID: audit_rules_time_watch_localtime
Time: 2014-10-07 12:27
Severity: low
Add the following to /etc/audit/audit.rules
:
-w /etc/localtime -p wa -k audit_time_rules
The -k option allows for the specification of a key in string form that can
be used for better reporting capability through ausearch and aureport and
should always be used.
Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Security identifiers
- CCE-27172-6
Result for Record Events that Modify User/Group Information
Result: fail
Rule ID: audit_account_changes
Time: 2014-10-07 12:27
Severity: low
Add the following to /etc/audit/audit.rules
, in order
to capture events that modify account changes:
# audit_account_changes
-w /etc/group -p wa -k audit_account_changes
-w /etc/passwd -p wa -k audit_account_changes
-w /etc/gshadow -p wa -k audit_account_changes
-w /etc/shadow -p wa -k audit_account_changes
-w /etc/security/opasswd -p wa -k audit_account_changes
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Security identifiers
- CCE-26664-3
Result for Record Events that Modify the System's Network Environment
Result: fail
Rule ID: audit_network_modifications
Time: 2014-10-07 12:27
Severity: low
Add the following to /etc/audit/audit.rules
, setting
ARCH to either b32 or b64 as appropriate for your system:
# audit_network_modifications
-a always,exit -F arch=ARCH -S sethostname -S setdomainname -k audit_network_modifications
-w /etc/issue -p wa -k audit_network_modifications
-w /etc/issue.net -p wa -k audit_network_modifications
-w /etc/hosts -p wa -k audit_network_modifications
-w /etc/sysconfig/network -p wa -k audit_network_modifications
The network environment should not be modified by anything other than administrator action. Any change to network parameters should be audited.
Security identifiers
- CCE-26648-6
Result for Record Events that Modify the System's Mandatory Access Controls
Result: fail
Rule ID: audit_mac_changes
Time: 2014-10-07 12:27
Severity: low
Add the following to /etc/audit/audit.rules
:
-w /etc/selinux/ -p wa -k MAC-policy
The system's mandatory access policy (SELinux) should not be arbitrarily changed by anything other than administrator action. All changes to MAC policy should be audited.
Security identifiers
- CCE-26657-7
Result for Record Events that Modify the System's Discretionary Access Controls - chmod
Result: fail
Rule ID: audit_rules_dac_modification_chmod
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S chmod -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S chmod -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-26280-8
Result for Record Events that Modify the System's Discretionary Access Controls - chown
Result: fail
Rule ID: audit_rules_dac_modification_chown
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S chown -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S chown -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27173-4
Result for Record Events that Modify the System's Discretionary Access Controls - fchmod
Result: fail
Rule ID: audit_rules_dac_modification_fchmod
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S fchmod -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fchmod -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27174-2
Result for Record Events that Modify the System's Discretionary Access Controls - fchmodat
Result: fail
Rule ID: audit_rules_dac_modification_fchmodat
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S fchmodat -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fchmodat -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27175-9
Result for Record Events that Modify the System's Discretionary Access Controls - fchown
Result: fail
Rule ID: audit_rules_dac_modification_fchown
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S fchown -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fchown -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27177-5
Result for Record Events that Modify the System's Discretionary Access Controls - fchownat
Result: fail
Rule ID: audit_rules_dac_modification_fchownat
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S fchownat -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fchownat -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27178-3
Result for Record Events that Modify the System's Discretionary Access Controls - fremovexattr
Result: fail
Rule ID: audit_rules_dac_modification_fremovexattr
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S fremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27179-1
Result for Record Events that Modify the System's Discretionary Access Controls - fsetxattr
Result: fail
Rule ID: audit_rules_dac_modification_fsetxattr
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S fsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S fsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27180-9
Result for Record Events that Modify the System's Discretionary Access Controls - lchown
Result: fail
Rule ID: audit_rules_dac_modification_lchown
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S lchown -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S lchown -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27181-7
Result for Record Events that Modify the System's Discretionary Access Controls - lremovexattr
Result: fail
Rule ID: audit_rules_dac_modification_lremovexattr
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S lremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S lremovexattr -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27182-5
Result for Record Events that Modify the System's Discretionary Access Controls - lsetxattr
Result: fail
Rule ID: audit_rules_dac_modification_lsetxattr
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S lsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S lsetxattr -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27183-3
Result for Record Events that Modify the System's Discretionary Access Controls - removexattr
Result: fail
Rule ID: audit_rules_dac_modification_removexattr
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S removexattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S removexattr -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27184-1
Result for Record Events that Modify the System's Discretionary Access Controls - setxattr
Result: fail
Rule ID: audit_rules_dac_modification_setxattr
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
permission changes for all users and root. Add the following to
/etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S setxattr -F auid>=500 -F auid!=4294967295 -k perm_mod
If the system is 64 bit then also add the following:
-a always,exit -F arch=b64 -S setxattr -F auid>=500 -F auid!=4294967295 -k perm_mod
Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Security identifiers
- CCE-27185-8
Result for Ensure auditd Collects Unauthorized Access Attempts to Files (unsuccessful)
Result: fail
Rule ID: audit_rules_unsuccessful_file_modification
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect
unauthorized file accesses for all users and root. Add the following
to /etc/audit/audit.rules
:
-a always,exit -F arch=b32 -S creat -S open -S openat -S open_by_handle_at -S truncate -S ftruncate -F exit=-EACCES -F auid>=500 -F auid!=4294967295 -k access
-a always,exit -F arch=b32 -S creat -S open -S openat -S open_by_handle_at -S truncate -S ftruncate -F exit=-EPERM -F auid>=500 -F auid!=4294967295 -k access
-a always,exit -F arch=b64 -S creat -S open -S openat -S open_by_handle_at -S truncate -S ftruncate -F exit=-EACCES -F auid>=500 -F auid!=4294967295 -k access
-a always,exit -F arch=b64 -S creat -S open -S openat -S open_by_handle_at -S truncate -S ftruncate -F exit=-EPERM -F auid>=500 -F auid!=4294967295 -k access
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Security identifiers
- CCE-26712-0
Result for Ensure auditd Collects Information on the Use of Privileged Commands
Result: fail
Rule ID: audit_rules_privileged_commands
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect the execution of privileged commands for all users and root. To find the relevant setuid / setgid programs:
$ sudo find / -xdev -type f -perm -4000 -o -perm -2000 2>/dev/null
Then, for each setuid / setgid program on the system, add a line of the following form to
/etc/audit/audit.rules
, where SETUID_PROG_PATH is the full path to each setuid / setgid program
in the list:
-a always,exit -F path=SETUID_PROG_PATH -F perm=x -F auid>=500 -F auid!=4294967295 -k privileged
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
Security identifiers
- CCE-26457-2
check if count of found privileged commands on the system is equal to count of audit.rules privileged commands definitions
var ref | value |
oval:ssg:var:2331 | 31 |
Result for Ensure auditd Collects Information on Exporting to Media (successful)
Result: fail
Rule ID: audit_media_exports
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect media
exportation events for all users and root. Add the following to
/etc/audit/audit.rules
, setting ARCH to either b32 or b64 as
appropriate for your system:
-a always,exit -F arch=ARCH -S mount -F auid>=500 -F auid!=4294967295 -k export
The unauthorized exportation of data to external media could result in an information leak where classified information, Privacy Act information, and intellectual property could be lost. An audit trail should be created each time a filesystem is mounted to help identify and guard against information loss.
Security identifiers
- CCE-26573-6
Result for Ensure auditd Collects File Deletion Events by User
Result: fail
Rule ID: audit_rules_file_deletion_events
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect file
deletion events for all users and root. Add the following to
/etc/audit/audit.rules
, setting ARCH to either b32 or b64 as
appropriate for your system:
-a always,exit -F arch=ARCH -S rmdir -S unlink -S unlinkat -S rename -S renameat -F auid>=500 -F auid!=4294967295 -k delete
Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
Security identifiers
- CCE-26651-0
Result for Ensure auditd Collects System Administrator Actions
Result: fail
Rule ID: audit_sysadmin_actions
Time: 2014-10-07 12:27
Severity: low
At a minimum the audit system should collect
administrator actions for all users and root. Add the following to
/etc/audit/audit.rules
:
-w /etc/sudoers -p wa -k actions
The actions taken by system administrators should be audited to keep a record of what was executed on the system, as well as, for accountability purposes.
Security identifiers
- CCE-26662-7
Result for Ensure auditd Collects Information on Kernel Module Loading and Unloading
Result: fail
Rule ID: audit_rules_kernel_module_loading
Time: 2014-10-07 12:27
Severity: low
Add the following to /etc/audit/audit.rules
in order
to capture kernel module loading and unloading events, setting ARCH to either b32 or b64 as appropriate for your system:
-w /sbin/insmod -p x -k modules
-w /sbin/rmmod -p x -k modules
-w /sbin/modprobe -p x -k modules
-a always,exit -F arch=ARCH -S init_module -S delete_module -k modules
The addition/removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
Security identifiers
- CCE-26611-4
Result for Make the auditd Configuration Immutable
Result: fail
Rule ID: audit_config_immutable
Time: 2014-10-07 12:27
Severity: low
Add the following to /etc/audit/audit.rules
in order
to make the configuration immutable:
-e 2
With this setting, a reboot will be required to change any
audit rules.Making the audit configuration immutable prevents accidental as well as malicious modification of the audit rules, although it may be problematic if legitimate changes are needed during system operation
Security identifiers
- CCE-26612-2
Result for Disable xinetd Service
Result: pass
Rule ID: disable_xinetd
Time: 2014-10-07 12:27
Severity: medium
The xinetd
service can be disabled with the following command:
# chkconfig xinetd off
The xinetd service provides a dedicated listener service for some programs, which is no longer necessary for commonly-used network services. Disabling it ensures that these uncommon services are not running, and also prevents attacks against xinetd itself.
Security identifiers
- CCE-27046-2
Result for Uninstall xinetd Package
Result: pass
Rule ID: uninstall_xinetd
Time: 2014-10-07 12:27
Severity: low
The xinetd
package can be uninstalled with the following command:
$ sudo yum erase xinetd
Removing the xinetd
package decreases the risk of the
xinetd service's accidental (or intentional) activation.
Security identifiers
- CCE-27005-8
Remediation script
if rpm -qa | grep -q xinetd; then
yum -y remove xinetd
fi
Result for Disable telnet Service
Result: pass
Rule ID: disable_telnet_service
Time: 2014-10-07 12:27
Severity: high
The telnet
service can be disabled with the following command:
# chkconfig telnet off
The telnet protocol uses unencrypted network communication, which means that data from the login session, including passwords and all other information transmitted during the session, can be stolen by eavesdroppers on the network. The telnet protocol is also subject to man-in-the-middle attacks.
Security identifiers
- CCE-26836-7
Result for Uninstall telnet-server Package
Result: pass
Rule ID: uninstall_telnet_server
Time: 2014-10-07 12:27
Severity: high
The telnet-server
package can be uninstalled with
the following command:
$ sudo yum erase telnet-server
Removing the telnet-server
package decreases the risk of the
telnet service's accidental (or intentional) activation.
Security identifiers
- CCE-27073-6
Remediation script
if rpm -qa | grep -q telnet-server; then
yum -y remove telnet-server
fi
Result for Uninstall rsh-server Package
Result: pass
Rule ID: uninstall_rsh-server
Time: 2014-10-07 12:27
Severity: high
The rsh-server
package can be uninstalled with
the following command:
$ sudo yum erase rsh-server
The rsh-server
package provides several obsolete and insecure
network services. Removing it
decreases the risk of those services' accidental (or intentional)
activation.
Security identifiers
- CCE-27062-9
Result for Uninstall ypserv Package
Result: pass
Rule ID: uninstall_ypserv
Time: 2014-10-07 12:27
Severity: medium
The ypserv
package can be uninstalled with
the following command:
$ sudo yum erase ypserv
Removing the ypserv
package decreases the risk of the
accidental (or intentional) activation of NIS or NIS+ services.
Security identifiers
- CCE-27079-3
Remediation script
if rpm -qa | grep -q ypserv; then
yum -y remove ypserv
fi
Result for Disable ypbind Service
Result: pass
Rule ID: disable_ypbind
Time: 2014-10-07 12:27
Severity: medium
The ypbind
service, which allows the system to act as a client in
a NIS or NIS+ domain, should be disabled.
The ypbind
service can be disabled with the following command:
# chkconfig ypbind off
Disabling the ypbind
service ensures the system is not acting
as a client in a NIS or NIS+ domain.
Security identifiers
- CCE-26894-6
Result for Disable tftp Service
Result: pass
Rule ID: disable_tftp
Time: 2014-10-07 12:27
Severity: medium
The tftp
service should be disabled.
The tftp
service can be disabled with the following command:
# chkconfig tftp off
Disabling the tftp
service ensures the system is not acting
as a TFTP server, which does not provide encryption or authentication.
Security identifiers
- CCE-27055-3
Result for Uninstall tftp-server Package
Result: pass
Rule ID: uninstall_tftp-server
Time: 2014-10-07 12:27
Severity: medium
The tftp-server
package can be removed with the following command:
# yum erase tftp-server
Removing the tftp-server
package decreases the risk of the
accidental (or intentional) activation of tftp services.
Security identifiers
- CCE-26946-4
Result for Disable KDump Kernel Crash Analyzer (kdump)
Result: pass
Rule ID: service_kdump_disabled
Time: 2014-10-07 12:27
Severity: low
The kdump
service provides a kernel crash dump analyzer. It uses the kexec
system call to boot a secondary kernel ("capture" kernel) following a system
crash, which can load information from the crashed kernel for analysis.
The kdump
service can be disabled with the following command:
# chkconfig kdump off
Unless the system is used for kernel development or testing, there is little need to run the kdump service.
Security identifiers
- CCE-26850-8
Remediation script
#
# Disable kdump for all run levels
#
chkconfig --level 0123456 kdump off
#
# Stop kdump if currently running
#
service kdump stop
Result for Disable Portreserve (portreserve)
Result: error
Rule ID: service_portreserve_disabled
Time: 2014-10-07 12:28
Severity: low
The portreserve
service is a TCP port reservation utility that can
be used to prevent portmap from binding to well known TCP ports that are
required for other services.
The portreserve
service can be disabled with the following command:
# chkconfig portreserve off
The portreserve
service provides helpful functionality by
preventing conflicting usage of ports in the reserved port range, but it can be
disabled if not needed.
Security identifiers
- CCE-27258-3
Remediation script
#
# Disable portreserve for all run levels
#
chkconfig --level 0123456 portreserve off
#
# Stop portreserve if currently running
#
service portreserve stop
Runlevel test
service name | runlevel | start | kill |
portreserve | 2 | true | false |
Runlevel test
service name | runlevel | start | kill |
portreserve | 3 | true | false |
Runlevel test
service name | runlevel | start | kill |
portreserve | 4 | true | false |
Runlevel test
service name | runlevel | start | kill |
portreserve | 5 | true | false |
Result for Disable Red Hat Network Service (rhnsd)
Result: error
Rule ID: service_rhnsd_disabled
Time: 2014-10-07 12:28
Severity: low
The Red Hat Network service automatically queries Red Hat Network
servers to determine whether there are any actions that should be executed,
such as package updates. This only occurs if the system was registered to an
RHN server or satellite and managed as such.
The rhnsd
service can be disabled with the following command:
# chkconfig rhnsd off
Although systems management and patching is extremely important to
system security, management by a system outside the enterprise enclave is not
desirable for some environments. However, if the system is being managed by RHN or
RHN Satellite Server the rhnsd
daemon can remain on.
Security identifiers
- CCE-26846-6
Remediation script
#
# Disable rhnsd for all run levels
#
chkconfig --level 0123456 rhnsd off
#
# Stop rhnsd if currently running
#
service rhnsd stop
Runlevel test
service name | runlevel | start | kill |
rhnsd | 2 | true | false |
Runlevel test
service name | runlevel | start | kill |
rhnsd | 3 | true | false |
Runlevel test
service name | runlevel | start | kill |
rhnsd | 4 | true | false |
Runlevel test
service name | runlevel | start | kill |
rhnsd | 5 | true | false |
Result for Enable cron Service
Result: pass
Rule ID: service_crond_enabled
Time: 2014-10-07 12:27
Severity: medium
The crond
service is used to execute commands at
preconfigured times. It is required by almost all systems to perform necessary
maintenance tasks, such as notifying root of system activity.
The crond
service can be enabled with the following command:
# chkconfig --level 2345 crond on
Due to its usage for maintenance and security-supporting tasks, enabling the cron daemon is essential.
Security identifiers
- CCE-27070-2
Remediation script
#
# Enable crond for all run levels
#
chkconfig --level 0123456 crond on
#
# Start crond if not currently running
#
service crond start
Result for Disable At Service (atd)
Result: error
Rule ID: service_atd_disabled
Time: 2014-10-07 12:28
Severity: low
The at
and batch
commands can be used to
schedule tasks that are meant to be executed only once. This allows delayed
execution in a manner similar to cron, except that it is not
recurring. The daemon atd
keeps track of tasks scheduled via
at
and batch
, and executes them at the specified time.
The atd
service can be disabled with the following command:
# chkconfig atd off
The atd
service could be used by an unsophisticated insider to carry
out activities outside of a normal login session, which could complicate
accountability. Furthermore, the need to schedule tasks with at
or
batch
is not common.
Security identifiers
- CCE-27249-2
Remediation script
#
# Disable atd for all run levels
#
chkconfig --level 0123456 atd off
#
# Stop atd if currently running
#
service atd stop
Runlevel test
service name | runlevel | start | kill |
atd | 3 | true | false |
Runlevel test
service name | runlevel | start | kill |
atd | 4 | true | false |
Runlevel test
service name | runlevel | start | kill |
atd | 5 | true | false |
Result for Allow Only SSH Protocol 2
Result: pass
Rule ID: sshd_allow_only_protocol2
Time: 2014-10-07 12:27
Severity: high
Only SSH protocol version 2 connections should be
permitted. The default setting in
/etc/ssh/sshd_config
is correct, and can be
verified by ensuring that the following
line appears:
Protocol 2
SSH protocol version 1 suffers from design flaws that result in security vulnerabilities and should not be used.
Security identifiers
- CCE-27072-8
Remediation script
grep -qi ^Protocol /etc/ssh/sshd_config && \
sed -i "s/Protocol.*/Protocol 2/gI" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
echo "Protocol 2" >> /etc/ssh/sshd_config
fi
Result for Set SSH Idle Timeout Interval
Result: fixed
Rule ID: sshd_set_idle_timeout
Time: 2014-10-07 12:28
Severity: low
SSH allows administrators to set an idle timeout
interval.
After this interval has passed, the idle user will be
automatically logged out.
To set an idle timeout interval, edit the following line in /etc/ssh/sshd_config
as
follows:
ClientAliveInterval 300
The timeout interval is given in seconds. To have a timeout
of 15 minutes, set interval to 900.
If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made here. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle.
Causing idle users to be automatically logged out guards against compromises one system leading trivially to compromises on another.
Security identifiers
- CCE-26919-1
Remediation script
sshd_idle_timeout_value="300"
grep -q ^ClientAliveInterval /etc/ssh/sshd_config && \
sed -i "s/ClientAliveInterval.*/ClientAliveInterval $sshd_idle_timeout_value/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
echo "ClientAliveInterval $sshd_idle_timeout_value" >> /etc/ssh/sshd_config
fi
Result for Set SSH Client Alive Count
Result: fixed
Rule ID: sshd_set_keepalive
Time: 2014-10-07 12:28
Severity: low
To ensure the SSH idle timeout occurs precisely when the ClientAliveCountMax
is set,
edit /etc/ssh/sshd_config
as
follows:
ClientAliveCountMax 0
This ensures a user login will be terminated as soon as the ClientAliveCountMax
is reached.
Security identifiers
- CCE-26282-4
Remediation script
grep -q ^ClientAliveCountMax /etc/ssh/sshd_config && \
sed -i "s/ClientAliveCountMax.*/ClientAliveCountMax 0/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
echo "ClientAliveCountMax 0" >> /etc/ssh/sshd_config
fi
Result for Disable SSH Support for .rhosts Files
Result: pass
Rule ID: sshd_disable_rhosts
Time: 2014-10-07 12:27
Severity: medium
SSH can emulate the behavior of the obsolete rsh
command in allowing users to enable insecure access to their
accounts via .rhosts
files.
To ensure this behavior is disabled, add or correct the
following line in /etc/ssh/sshd_config
:
IgnoreRhosts yes
SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
Security identifiers
- CCE-27124-7
Remediation script
grep -q ^IgnoreRhosts /etc/ssh/sshd_config && \
sed -i "s/IgnoreRhosts.*/IgnoreRhosts yes/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
echo "IgnoreRhosts yes" >> /etc/ssh/sshd_config
fi
Result for Disable Host-Based Authentication
Result: pass
Rule ID: disable_host_auth
Time: 2014-10-07 12:27
Severity: medium
SSH's cryptographic host-based authentication is
more secure than .rhosts
authentication. However, it is
not recommended that hosts unilaterally trust one another, even
within an organization.
To disable host-based authentication, add or correct the
following line in /etc/ssh/sshd_config
:
HostbasedAuthentication no
SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
Security identifiers
- CCE-27091-8
Remediation script
grep -q ^HostbasedAuthentication /etc/ssh/sshd_config && \
sed -i "s/HostbasedAuthentication.*/HostbasedAuthentication no/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
echo "HostbasedAuthentication no" >> /etc/ssh/sshd_config
fi
Result for Disable SSH Root Login
Result: fixed
Rule ID: sshd_disable_root_login
Time: 2014-10-07 12:28
Severity: medium
The root user should never be allowed to login to a
system directly over a network.
To disable root login via SSH, add or correct the following line
in /etc/ssh/sshd_config
:
PermitRootLogin no
Permitting direct root login reduces auditable information about who ran privileged commands on the system and also allows direct attack attempts on root's password.
Security identifiers
- CCE-27100-7
Remediation script
SSHD_CONFIG='/etc/ssh/sshd_config'
# Obtain line number of first uncommented case-insensitive occurrence of Match
# block directive (possibly prefixed with whitespace) present in $SSHD_CONFIG
FIRST_MATCH_BLOCK=$(sed -n '/^[[:space:]]*Match[^\n]*/I{=;q}' $SSHD_CONFIG)
# Obtain line number of first uncommented case-insensitive occurence of
# PermitRootLogin directive (possibly prefixed with whitespace) present in
# $SSHD_CONFIG
FIRST_PERMIT_ROOT_LOGIN=$(sed -n '/^[[:space:]]*PermitRootLogin[^\n]*/I{=;q}' $SSHD_CONFIG)
# Case: Match block directive not present in $SSHD_CONFIG
if [ -z "$FIRST_MATCH_BLOCK" ]
then
# Case: PermitRootLogin directive not present in $SSHD_CONFIG yet
if [ -z "$FIRST_PERMIT_ROOT_LOGIN" ]
then
# Append 'PermitRootLogin no' at the end of $SSHD_CONFIG
echo -e "\nPermitRootLogin no" >> $SSHD_CONFIG
# Case: PermitRootLogin directive present in $SSHD_CONFIG already
else
# Replace first uncommented case-insensitive occurrence
# of PermitRootLogin directive
sed -i "$FIRST_PERMIT_ROOT_LOGIN s/^[[:space:]]*PermitRootLogin.*$/PermitRootLogin no/I" $SSHD_CONFIG
fi
# Case: Match block directive present in $SSHD_CONFIG
else
# Case: PermitRootLogin directive not present in $SSHD_CONFIG yet
if [ -z "$FIRST_PERMIT_ROOT_LOGIN" ]
then
# Prepend 'PermitRootLogin no' before first uncommented
# case-insensitive occurrence of Match block directive
sed -i "$FIRST_MATCH_BLOCK s/^\([[:space:]]*Match[^\n]*\)/PermitRootLogin no\n\1/I" $SSHD_CONFIG
# Case: PermitRootLogin directive present in $SSHD_CONFIG and placed
# before first Match block directive
elif [ "$FIRST_PERMIT_ROOT_LOGIN" -lt "$FIRST_MATCH_BLOCK" ]
then
# Replace first uncommented case-insensitive occurrence
# of PermitRootLogin directive
sed -i "$FIRST_PERMIT_ROOT_LOGIN s/^[[:space:]]*PermitRootLogin.*$/PermitRootLogin no/I" $SSHD_CONFIG
# Case: PermitRootLogin directive present in $SSHD_CONFIG and placed
# after first Match block directive
else
# Prepend 'PermitRootLogin no' before first uncommented
# case-insensitive occurrence of Match block directive
sed -i "$FIRST_MATCH_BLOCK s/^\([[:space:]]*Match[^\n]*\)/PermitRootLogin no\n\1/I" $SSHD_CONFIG
fi
fi
Result for Disable SSH Access via Empty Passwords
Result: fixed
Rule ID: sshd_disable_empty_passwords
Time: 2014-10-07 12:28
Severity: high
To explicitly disallow remote login from accounts with
empty passwords, add or correct the following line in
/etc/ssh/sshd_config
:
PermitEmptyPasswords no
Any accounts with empty passwords should be disabled immediately, and PAM configuration
should prevent users from being able to assign themselves empty passwords.
Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.
Security identifiers
- CCE-26887-0
Remediation script
grep -q ^PermitEmptyPasswords /etc/ssh/sshd_config && \
sed -i "s/PermitEmptyPasswords.*/PermitEmptyPasswords no/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
echo "PermitEmptyPasswords no" >> /etc/ssh/sshd_config
fi
Result for Enable SSH Warning Banner
Result: fixed
Rule ID: sshd_enable_warning_banner
Time: 2014-10-07 12:28
Severity: medium
To enable the warning banner and ensure it is consistent
across the system, add or correct the following line in /etc/ssh/sshd_config
:
Banner /etc/issue
Another section contains information on how to create an
appropriate system-wide warning banner.
The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution.
Security identifiers
- CCE-27112-2
Remediation script
grep -q ^Banner /etc/ssh/sshd_config && \
sed -i "s/Banner.*/Banner \/etc\/issue/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
echo "Banner /etc/issue" >> /etc/ssh/sshd_config
fi
Result for Do Not Allow SSH Environment Options
Result: fixed
Rule ID: sshd_do_not_permit_user_env
Time: 2014-10-07 12:28
Severity: low
To ensure users are not able to present
environment options to the SSH daemon, add or correct the following line
in /etc/ssh/sshd_config
:
PermitUserEnvironment no
SSH environment options potentially allow users to bypass access restriction in some configurations.
Security identifiers
- CCE-27201-3
Remediation script
grep -q ^PermitUserEnvironment /etc/ssh/sshd_config && \
sed -i "s/PermitUserEnvironment.*/PermitUserEnvironment no/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
echo "PermitUserEnvironment no" >> /etc/ssh/sshd_config
fi
Result for Use Only Approved Ciphers
Result: fixed
Rule ID: sshd_use_approved_ciphers
Time: 2014-10-07 12:28
Severity: medium
Limit the ciphers to those algorithms which are FIPS-approved.
Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode.
The following line in /etc/ssh/sshd_config
demonstrates use of FIPS-approved ciphers:
Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc
The man page sshd_config(5)
contains a list of supported ciphers.
Approved algorithms should impart some level of confidence in their implementation. These are also required for compliance.
Security identifiers
- CCE-26555-3
Remediation script
grep -q ^Ciphers /etc/ssh/sshd_config && \
sed -i "s/Ciphers.*/Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc/g" /etc/ssh/sshd_config
if ! [ $? -eq 0 ]; then
echo "Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc" >> /etc/ssh/sshd_config
fi
Result for Disable Avahi Server Software
Result: pass
Rule ID: disable_avahi
Time: 2014-10-07 12:27
Severity: low
The avahi-daemon
service can be disabled with the following command:
# chkconfig avahi-daemon off
Because the Avahi daemon service keeps an open network port, it is subject to network attacks. Its functionality is convenient but is only appropriate if the local network can be trusted.
Security identifiers
- CCE-27087-6
Result for Disable DHCP Service
Result: pass
Rule ID: disable_dhcp_server
Time: 2014-10-07 12:27
Severity: medium
The dhcpd
service should be disabled on
any system that does not need to act as a DHCP server.
The dhcpd
service can be disabled with the following command:
# chkconfig dhcpd off
Unmanaged or unintentionally activated DHCP servers may provide faulty information to clients, interfering with the operation of a legitimate site DHCP server if there is one.
Security identifiers
- CCE-27074-4
Result for Uninstall DHCP Server Package
Result: pass
Rule ID: uninstall_dhcp_server
Time: 2014-10-07 12:27
Severity: medium
If the system does not need to act as a DHCP server,
the dhcp package can be uninstalled.
The dhcp
package can be removed with the following command:
# yum erase dhcp
Removing the DHCP server ensures that it cannot be easily or accidentally reactivated and disrupt network operation.
Security identifiers
- CCE-27120-5
Result for Enable the NTP Daemon
Result: error
Rule ID: service_ntpd_enabled
Time: 2014-10-07 12:28
Severity: medium
The ntpd
service can be enabled with the following command:
# chkconfig --level 2345 ntpd on
Enabling the ntpd
service ensures that the ntpd
service will be running and that the system will synchronize its time to
any servers specified. This is important whether the system is configured to be
a client (and synchronize only its own clock) or it is also acting as an NTP
server to other systems. Synchronizing time is essential for authentication
services such as Kerberos, but it is also important for maintaining accurate
logs and auditing possible security breaches.
The NTP daemon offers all of the functionality of ntpdate
, which is now
deprecated. Additional information on this is available at
http://support.ntp.org/bin/view/Dev/DeprecatingNtpdate
Security identifiers
- CCE-27093-4
Remediation script
#
# Enable ntpd for all run levels
#
chkconfig --level 0123456 ntpd on
#
# Start ntpd if not currently running
#
service ntpd start
Runlevel test
service name | runlevel | start | kill |
ntpd | 0 | false | true |
Runlevel test
service name | runlevel | start | kill |
ntpd | 1 | false | true |
Runlevel test
service name | runlevel | start | kill |
ntpd | 2 | false | true |
Runlevel test
service name | runlevel | start | kill |
ntpd | 3 | false | true |
Runlevel test
service name | runlevel | start | kill |
ntpd | 4 | false | true |
Runlevel test
service name | runlevel | start | kill |
ntpd | 5 | false | true |
Runlevel test
service name | runlevel | start | kill |
ntpd | 6 | false | true |
Result for Specify a Remote NTP Server
Result: pass
Rule ID: ntpd_specify_remote_server
Time: 2014-10-07 12:27
Severity: medium
To specify a remote NTP server for time synchronization, edit
the file /etc/ntp.conf
. Add or correct the following lines,
substituting the IP or hostname of a remote NTP server for ntpserver:
server ntpserver
This instructs the NTP software to contact that remote server to obtain time
data.
Synchronizing with an NTP server makes it possible to collate system logs from multiple sources or correlate computer events with real time events.
Security identifiers
- CCE-27098-3
Result for Uninstall Sendmail Package
Result: pass
Rule ID: package_sendmail_removed
Time: 2014-10-07 12:27
Severity: medium
Sendmail is not the default mail transfer agent and is
not installed by default.
The sendmail
package can be removed with the following command:
# yum erase sendmail
The sendmail software was not developed with security in mind and its design prevents it from being effectively contained by SELinux. Postfix should be used instead.
Security identifiers
- CCE-27515-6
Result for Disable Postfix Network Listening
Result: pass
Rule ID: postfix_network_listening
Time: 2014-10-07 12:27
Severity: medium
Edit the file /etc/postfix/main.cf
to ensure that only the following
inet_interfaces
line appears:
inet_interfaces = localhost
This ensures postfix
accepts mail messages
(such as cron job reports) from the local system only,
and not from the network, which protects it from network attack.
Security identifiers
- CCE-26780-7
Result for Configure LDAP Client to Use TLS For All Transactions
Result: pass
Rule ID: ldap_client_start_tls
Time: 2014-10-07 12:27
Severity: medium
Configure LDAP to enforce TLS use. First, edit the file
/etc/pam_ldap.conf
, and add or correct the following lines:
ssl start_tls
Then review the LDAP server and ensure TLS has been configured.
The ssl directive specifies whether to use ssl or not. If not specified it will default to no. It should be set to start_tls rather than doing LDAP over SSL.
Security identifiers
- CCE-26690-8
Result for Configure Certificate Directives for LDAP Use of TLS
Result: pass
Rule ID: ldap_client_tls_cacertpath
Time: 2014-10-07 12:27
Severity: medium
Ensure a copy of a trusted CA certificate has been placed in
the file /etc/pki/tls/CA/cacert.pem
. Configure LDAP to enforce TLS
use and to trust certificates signed by that CA. First, edit the file
/etc/pam_ldap.conf
, and add or correct either of the following lines:
tls_cacertdir /etc/pki/tls/CA
or
tls_cacertfile /etc/pki/tls/CA/cacert.pem
Then review the LDAP server and ensure TLS has been configured.
The tls_cacertdir or tls_cacertfile directives are required when tls_checkpeer is configured (which is the default for openldap versions 2.1 and up). These directives define the path to the trust certificates signed by the site CA.
Security identifiers
- CCE-27189-0
Result for Uninstall openldap-servers Package
Result: pass
Rule ID: package_openldap-servers_removed
Time: 2014-10-07 12:27
Severity: low
The openldap-servers
package should be removed if not in use.
Is this machine the OpenLDAP server? If not, remove the package.
$ sudo yum erase openldap-servers
The openldap-servers RPM is not installed by default on RHEL 6
machines. It is needed only by the OpenLDAP server, not by the
clients which use LDAP for authentication. If the system is not
intended for use as an LDAP Server it should be removed.
Unnecessary packages should not be installed to decrease the attack surface of the system. While this software is clearly essential on an LDAP server, it is not necessary on typical desktop or workstation systems.
Security identifiers
- CCE-26858-1
Result for Disable Network File System Lock Service (nfslock)
Result: error
Rule ID: service_nfslock_disabled
Time: 2014-10-07 12:28
Severity: low
The Network File System Lock (nfslock) service starts the required
remote procedure call (RPC) processes which allow clients to lock files on the
server. If the local machine is not configured to mount NFS filesystems then
this service should be disabled.
The nfslock
service can be disabled with the following command:
# chkconfig nfslock off
Security identifiers
- CCE-27104-9
Remediation script
#
# Disable nfslock for all run levels
#
chkconfig --level 0123456 nfslock off
#
# Stop nfslock if currently running
#
service nfslock stop
Runlevel test
service name | runlevel | start | kill |
nfslock | 3 | true | false |
Runlevel test
service name | runlevel | start | kill |
nfslock | 4 | true | false |
Runlevel test
service name | runlevel | start | kill |
nfslock | 5 | true | false |
Result for Disable Secure RPC Client Service (rpcgssd)
Result: error
Rule ID: service_rpcgssd_disabled
Time: 2014-10-07 12:28
Severity: low
The rpcgssd service manages RPCSEC GSS contexts required to secure protocols
that use RPC (most often Kerberos and NFS). The rpcgssd service is the
client-side of RPCSEC GSS. If the system does not require secure RPC then this
service should be disabled.
The rpcgssd
service can be disabled with the following command:
# chkconfig rpcgssd off
Security identifiers
- CCE-26864-9
Remediation script
#
# Disable rpcgssd for all run levels
#
chkconfig --level 0123456 rpcgssd off
#
# Stop rpcgssd if currently running
#
service rpcgssd stop
Runlevel test
service name | runlevel | start | kill |
rpcgssd | 3 | true | false |
Runlevel test
service name | runlevel | start | kill |
rpcgssd | 4 | true | false |
Runlevel test
service name | runlevel | start | kill |
rpcgssd | 5 | true | false |
Result for Disable RPC ID Mapping Service (rpcidmapd)
Result: error
Rule ID: service_rpcidmapd_disabled
Time: 2014-10-07 12:28
Severity: low
The rpcidmapd service is used to map user names and groups to UID
and GID numbers on NFSv4 mounts. If NFS is not in use on the local system then
this service should be disabled.
The rpcidmapd
service can be disabled with the following command:
# chkconfig rpcidmapd off
Security identifiers
- CCE-26870-6
Remediation script
#
# Disable rpcidmapd for all run levels
#
chkconfig --level 0123456 rpcidmapd off
#
# Stop rpcidmapd if currently running
#
service rpcidmapd stop
Runlevel test
service name | runlevel | start | kill |
rpcidmapd | 0 | false | false |
Runlevel test
service name | runlevel | start | kill |
rpcidmapd | 1 | false | false |
Runlevel test
service name | runlevel | start | kill |
rpcidmapd | 2 | false | false |
Runlevel test
service name | runlevel | start | kill |
rpcidmapd | 3 | false | false |
Runlevel test
service name | runlevel | start | kill |
rpcidmapd | 4 | false | false |
Runlevel test
service name | runlevel | start | kill |
rpcidmapd | 5 | false | false |
Runlevel test
service name | runlevel | start | kill |
rpcidmapd | 6 | false | false |
Result for Disable Network File Systems (netfs)
Result: error
Rule ID: service_netfs_disabled
Time: 2014-10-07 12:28
Severity: low
The netfs script manages the boot-time mounting of several types
of networked filesystems, of which NFS and Samba are the most common. If these
filesystem types are not in use, the script can be disabled, protecting the
system somewhat against accidental or malicious changes to /etc/fstab
and against flaws in the netfs script itself.
The netfs
service can be disabled with the following command:
# chkconfig netfs off
Security identifiers
- CCE-27137-9
Remediation script
#
# Disable netfs for all run levels
#
chkconfig --level 0123456 netfs off
#
# Stop netfs if currently running
#
service netfs stop
Runlevel test
service name | runlevel | start | kill |
netfs | 3 | true | false |
Runlevel test
service name | runlevel | start | kill |
netfs | 4 | true | false |
Runlevel test
service name | runlevel | start | kill |
netfs | 5 | true | false |
Result for Disable Secure RPC Server Service (rpcsvcgssd)
Result: pass
Rule ID: service_rpcsvcgssd_disabled
Time: 2014-10-07 12:27
Severity: low
The rpcsvcgssd service manages RPCSEC GSS contexts required to
secure protocols that use RPC (most often Kerberos and NFS). The rpcsvcgssd
service is the server-side of RPCSEC GSS. If the system does not require secure
RPC then this service should be disabled.
The rpcsvcgssd
service can be disabled with the following command:
# chkconfig rpcsvcgssd off
Unnecessary services should be disabled to decrease the attack surface of the system.
Security identifiers
- CCE-27122-1
Remediation script
#
# Disable rpcsvcgssd for all run levels
#
chkconfig --level 0123456 rpcsvcgssd off
#
# Stop rpcsvcgssd if currently running
#
service rpcsvcgssd stop
Result for Mount Remote Filesystems with nodev
Result: pass
Rule ID: use_nodev_option_on_nfs_mounts
Time: 2014-10-07 12:27
Severity: medium
Add the nodev
option to the fourth column of
/etc/fstab
for the line which controls mounting of
any NFS mounts.
Legitimate device files should only exist in the /dev directory. NFS mounts should not present device files to users.
Security identifiers
- CCE-27090-0
Result for Mount Remote Filesystems with nosuid
Result: pass
Rule ID: use_nosuid_option_on_nfs_mounts
Time: 2014-10-07 12:27
Severity: medium
Add the nosuid
option to the fourth column of
/etc/fstab
for the line which controls mounting of
any NFS mounts.
NFS mounts should not present suid binaries to users. Only vendor-supplied suid executables should be installed to their default location on the local filesystem.
Security identifiers
- CCE-26972-0
Result for Disable DNS Server
Result: pass
Rule ID: disable_dns_server
Time: 2014-10-07 12:27
Severity: low
The named
service can be disabled with the following command:
# chkconfig named off
All network services involve some risk of compromise due to implementation flaws and should be disabled if possible.
Security identifiers
- CCE-26873-0
Result for Uninstall bind Package
Result: pass
Rule ID: uninstall_bind
Time: 2014-10-07 12:27
Severity: low
To remove the bind
package, which contains the
named
service, run the following command:
$ sudo yum erase bind
If there is no need to make DNS server software available, removing it provides a safeguard against its activation.
Security identifiers
- CCE-27030-6
Result for Disable vsftpd Service
Result: pass
Rule ID: disable_vsftpd
Time: 2014-10-07 12:27
Severity: low
The vsftpd
service can be disabled with the following command:
# chkconfig vsftpd off
Running FTP server software provides a network-based avenue of attack, and should be disabled if not needed. Furthermore, the FTP protocol is unencrypted and creates a risk of compromising sensitive information.
Security identifiers
- CCE-26948-0
Remediation script
if service vsftpd status >/dev/null; then
service vsftpd stop
fi
Result for Uninstall vsftpd Package
Result: pass
Rule ID: uninstall_vsftpd
Time: 2014-10-07 12:27
Severity: low
The vsftpd
package can be removed with the following command:
# yum erase vsftpd
Removing the vsftpd package decreases the risk of its accidental activation.
Security identifiers
- CCE-26687-4
Result for Disable httpd Service
Result: pass
Rule ID: disable_httpd
Time: 2014-10-07 12:27
Severity: low
The httpd
service can be disabled with the following command:
# chkconfig httpd off
Running web server software provides a network-based avenue of attack, and should be disabled if not needed.
Security identifiers
- CCE-27075-1
Result for Uninstall httpd Package
Result: pass
Rule ID: uninstall_httpd
Time: 2014-10-07 12:27
Severity: low
The httpd
package can be removed with the following command:
# yum erase httpd
If there is no need to make the web server software available, removing it provides a safeguard against its activation.
Security identifiers
- CCE-27133-8
Result for Disable Dovecot Service
Result: pass
Rule ID: disable_dovecot
Time: 2014-10-07 12:27
Severity: low
The dovecot
service can be disabled with the following command:
# chkconfig dovecot off
Running an IMAP or POP3 server provides a network-based avenue of attack, and should be disabled if not needed.
Security identifiers
- CCE-26922-5
Result for Uninstall dovecot Package
Result: pass
Rule ID: uninstall_dovecot
Time: 2014-10-07 12:27
Severity: low
The dovecot
package can be uninstalled
with the following command:
$ sudo yum erase dovecot
If there is no need to make the Dovecot software available, removing it provides a safeguard against its activation.
Security identifiers
- CCE-27039-7
Result for Disable Samba
Result: pass
Rule ID: disable_smb_server
Time: 2014-10-07 12:27
Severity: low
The smb
service can be disabled with the following command:
# chkconfig smb off
Running a Samba server provides a network-based avenue of attack, and should be disabled if not needed.
Security identifiers
- CCE-27143-7
Result for Require Client SMB Packet Signing, if using smbclient
Result: fail
Rule ID: require_smb_client_signing
Time: 2014-10-07 12:27
Severity: low
To require samba clients running smbclient
to use
packet signing, add the following to the [global]
section
of the Samba configuration file, /etc/samba/smb.conf
:
client signing = mandatory
Requiring samba clients such as smbclient
to use packet
signing ensures they can
only communicate with servers that support packet signing.
Packet signing can prevent man-in-the-middle attacks which modify SMB packets in transit.
Security identifiers
- CCE-26328-5
Result for Require Client SMB Packet Signing, if using mount.cifs
Result: pass
Rule ID: require_smb_client_signing_mount.cifs
Time: 2014-10-07 12:27
Severity: low
Require packet signing of clients who mount Samba
shares using the mount.cifs
program (e.g., those who specify shares
in /etc/fstab
). To do so, ensure signing options (either
sec=krb5i
or sec=ntlmv2i
) are used.
See the mount.cifs(8)
man page for more information. A Samba
client should only communicate with servers who can support SMB
packet signing.
Packet signing can prevent man-in-the-middle attacks which modify SMB packets in transit.
Security identifiers
- CCE-26792-2
Result for Disable Squid
Result: pass
Rule ID: disable_squid
Time: 2014-10-07 12:27
Severity: low
The squid
service can be disabled with the following command:
# chkconfig squid off
Running proxy server software provides a network-based avenue of attack, and should be removed if not needed.
Security identifiers
- CCE-27146-0
Result for Uninstall squid Package
Result: pass
Rule ID: uninstall_squid
Time: 2014-10-07 12:27
Severity: low
The squid
package can be removed with the following command:
# yum erase squid
If there is no need to make the proxy server software available, removing it provides a safeguard against its activation.
Security identifiers
- CCE-26977-9
Result for Disable snmpd Service
Result: pass
Rule ID: disable_snmpd
Time: 2014-10-07 12:27
Severity: low
The snmpd
service can be disabled with the following command:
# chkconfig snmpd off
Running SNMP software provides a network-based avenue of attack, and should be disabled if not needed.
Security identifiers
- CCE-26906-8
Result for Uninstall net-snmp Package
Result: pass
Rule ID: uninstall_net-snmp
Time: 2014-10-07 12:27
Severity: low
The net-snmp
package provides the snmpd service.
The net-snmpd
package can be removed with the following command:
# yum erase net-snmpd
If there is no need to run SNMP server software, removing the package provides a safeguard against its activation.
Security identifiers
- CCE-26332-7