Title

The time synchronization configuration file (such as /etc/ntp.conf) must not have an extended ACL. (Cat II impact)

Discussion

A synchronized system clock is critical for the enforcement of time-based policies and the correlation of logs and audit records with other systems. If an illicit time source is used for synchronization, the integrity of system logs and the security of the system could be compromised. If the configuration files controlling time synchronization are not protected, unauthorized modifications could result in the failure of time synchronization.

Check Content

Check for an extended ACL on the NTP configuration file. # ls -l /etc/inet/ntp.conf If the permissions contain a "+", the file has an extended ACL and this is a finding.

Fix Text

Remove the extended ACL from the file. # chmod A- /etc/inet/ntp.conf

Additional Identifiers

Rule ID: SV-227567r603266_rule

Vulnerability ID: V-227567

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

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