Title

The macOS system must audit the enforcement actions used to restrict access associated with changes to the system. (Cat II impact)

Discussion

By auditing access restriction enforcement, changes to application and OS configuration files can be audited. Without auditing the enforcement of access restrictions, it will be difficult to identify attempted attacks and an audit trail will not be available for forensic investigation. Enforcement actions are the methods or mechanisms used to prevent unauthorized changes to configuration settings. Enforcement action methods may be as simple as denying access to a file based on the application of file permissions (access restriction). Audit items may consist of lists of actions blocked by access restrictions or changes identified after the fact. Enforcement actions are logged by way of the "fm" flag, which audits permission changes; "-fr" and "-fw", which denote failed attempts to read or write to a file; and "-fd", which audits failed file deletion. Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000365-GPOS-00152, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-OS-000474-GPOS-00219

Check Content

Verify the macOS system is configured to audit enforcement actions with the following command: /usr/bin/sudo /usr/bin/grep ^flags /etc/security/audit_control If "fm", "-fr", "-fw", and "-fd" are not listed in the result of the check, this is a finding.

Fix Text

Configure the macOS system to audit enforcement actions with the following command: /usr/bin/sudo /usr/bin/sed -i.bak '/^flags/ s/$/,fm,-fr,-fw,-fd/' /etc/security/audit_control; /usr/bin/sudo /usr/sbin/audit -s A text editor may also be used to implement the required updates to the "/etc/security/audit_control" file.

Additional Identifiers

Rule ID: SV-257178r905167_rule

Vulnerability ID: V-257178

Group Title: SRG-OS-000064-GPOS-00033

Expert Comments

CCIs tied to check.

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