Title

The audit system must be configured to audit account modification. (Cat III impact)

Discussion

If the system is not configured to audit certain activities and write them to an audit log, it is more difficult to detect and track system compromises and damages incurred during a system compromise.

Check Content

Determine if execution of the usermod and groupmod executable are audited. # auditctl -l | egrep '(usermod|groupmod)' If either usermod or groupmod are not listed with a permissions filter of at least 'x', this is a finding. Determine if /etc/passwd, /etc/shadow, /etc/group, and /etc/gshadow are audited for writing. # auditctl -l | egrep '(/etc/passwd|/etc/shadow|/etc/group|/etc/gshadow)' If any of these are not listed with a permissions filter of at least 'w', this is a finding.

Fix Text

Configure execute auditing of the usermod and groupmod executables. Add the following to the audit.rules file: -w /usr/sbin/usermod -p x -k usermod -w /usr/sbin/groupmod -p x -k groupmod Configure append auditing of the passwd, shadow, group, and gshadow files. Add the following to the audit.rules file: -w /etc/passwd -p w -k passwd -w /etc/shadow -p w -k shadow -w /etc/group -p w -k group -w /etc/gshadow -p w -k gshadow Restart the auditd service. # rcauditd restart OR # service auditd restart

Additional Identifiers

Rule ID: SV-45308r1_rule

Vulnerability ID: V-22377

Group Title: GEN002751

Expert Comments

CCIs tied to check.

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