Vulnerability Discussion

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 System Security Manager (ISSM)/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.

Satisfies: SRG-OS-000363-GPOS-00150, SRG-OS-000445-GPOS-00199, SRG-OS-000446-GPOS-00200

Check

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

Note: A file integrity tool other than 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:

> zypper info aide | grep "Installed"

Installed: Yes

If the "aide" package is not installed, ask the 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:

> sudo grep -R 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

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 " [email protected]