Advanced Intrusion Detection Environment (AIDE) must verify the baseline SUSE operating system configuration at least weekly.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-77151	SLES-12-010500	SV-91847r3_rule		Medium

Description
Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the SUSE operating system. Changes to SUSE operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the SUSE operating system. The SUSE operating system's Information Management Officer (IMO)/Information System Security Officer (ISSO) and System Administrator (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.

Description

Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the SUSE operating system. Changes to SUSE operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the SUSE operating system. The SUSE operating system's Information Management Officer (IMO)/Information System Security Officer (ISSO) and System Administrator (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.

STIG	Date
SLES 12 Security Technical Implementation Guide	2018-09-27

Details

Check Text ( C-76761r3_chk )
Verify the SUSE operating system checks the baseline configuration for unauthorized changes at least once weekly. Note: A file integrity tool other than Advanced Intrusion Detection Environment (AIDE) may be used, but the tool must be executed at least once per week. Check to see if the "aide" package is installed on the system with the following command: # sudo zypper if aide \| grep "Installed" Installed: Yes If the "aide" package is not installed, ask the System Administrator (SA) how file integrity checks are performed on the system. Check for the presence of a cron job running daily or weekly on the system that executes AIDE to scan for changes to the system baseline. The command used in the following example looks at the daily cron job: Check the "/etc/cron" subdirectories for a "crontab" file controlling the execution of the file integrity application. For example, if AIDE is installed on the system, use the following command: # grep aide etc/crontab etc/cron.* /etc/crontab: 30 04 * * * /etc/aide If the file integrity application does not exist, or a "crontab" file does not exist in "/etc/crontab", the "/etc/cron.daily" subdirectory, or "/etc/cron.weekly" subdirectory, this is a finding.

Check Text ( C-76761r3_chk )

Verify the SUSE operating system checks the baseline configuration for unauthorized changes at least once weekly.

Note: A file integrity tool other than Advanced Intrusion Detection Environment (AIDE) may be used, but the tool must be executed at least once per week.

Check to see if the "aide" package is installed on the system with the following command:

# sudo zypper if aide | grep "Installed"

Installed: Yes

If the "aide" package is not installed, ask the System Administrator (SA) how file integrity checks are performed on the system.

Check for the presence of a cron job running daily or weekly on the system that executes AIDE to scan for changes to the system baseline. The command used in the following example looks at the daily cron job:

Check the "/etc/cron" subdirectories for a "crontab" file controlling the execution of the file integrity application. For example, if AIDE is installed on the system, use the following command:

# grep aide etc/crontab etc/cron.*
/etc/crontab: 30 04 * * * /etc/aide

If the file integrity application does not exist, or a "crontab" file does not exist in "/etc/crontab", the "/etc/cron.daily" subdirectory, or "/etc/cron.weekly" subdirectory, this is a finding.

Fix Text (F-83847r2_fix)
Configure the SUSE operating system to check the baseline configuration for unauthorized changes at least once weekly. If the "aide" package is not installed, install it with the following command: # sudo zypper in aide Configure the file integrity tool to automatically run on the system at least weekly. The following example output is generic. It will set cron to run AIDE weekly, but other file integrity tools may be used: # cat /etc/cron.weekly/aide 0 0 * * * /usr/sbin/aide --check \| /bin/mail -s "aide integrity check run for " root@notareal.email

Fix Text (F-83847r2_fix)

Configure the SUSE operating system to check the baseline configuration for unauthorized changes at least once weekly.

If the "aide" package is not installed, install it with the following command:

# sudo zypper in aide

Configure the file integrity tool to automatically run on the system at least weekly. The following example output is generic. It will set cron to run AIDE weekly, but other file integrity tools may be used:

# cat /etc/cron.weekly/aide
0 0 * * * /usr/sbin/aide --check | /bin/mail -s "aide integrity check run for " root@notareal.email