Title

The file integrity tool must notify the system administrator when changes to the baseline configuration or anomalies in the operation of any security functions are discovered. (Cat II impact)

Discussion

Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the Ubuntu operating system. Changes to Ubuntu operating system configurations can have unintended side effects, some of which may be relevant to security. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the Ubuntu operating system. The Ubuntu operating system's IMO/ISSO and SAs must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. Notifications provided by information systems include messages to local computer consoles, and/or hardware indications, such as lights. This capability must take into account operational requirements for availability for selecting an appropriate response. The organization may choose to shut down or restart the information system upon security function anomaly detection. Satisfies: SRG-OS-000363-GPOS-00150, SRG-OS-000447-GPOS-00201

Check Content

Verify that Advanced Intrusion Detection Environment (AIDE) notifies the system administrator when anomalies in the operation of any security functions are discovered. Check that AIDE notifies the system administrator when anomalies in the operation of any security functions are discovered with the following command: # sudo grep SILENTREPORTS /etc/default/aide SILENTREPORTS=no If the "/etc/default/aide" file does not exist, the cron job is configured with the "SILENTREPORTS=yes" option, or the line is commented out, this is a finding.

Fix Text

Modify the "SILENTREPORTS" parameter in "/etc/default/aide" file with a value "no" or if it does not already exist: SILENTREPORTS=no

Additional Identifiers

Rule ID: SV-214986r610931_rule

Vulnerability ID: V-214986

Group Title: SRG-OS-000363-GPOS-00150

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.