Title

NixOS must have time synchronization enabled. (Cat II impact)

Discussion

Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider setting time periods for different types of systems (e.g., financial, legal, or mission-critical systems). Organizations should also consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). This requirement is related to the comparison done every 24 hours in SRG-OS-000355 because a comparison must be done to determine the time difference.

Check Content

Verify NixOS synchronizes internal information system clocks to the authoritative time source when the time difference is greater than one second with the following command: $ grep -iR timesyncd.enable /etc/nixos/ services.timesyncd.enable = true; If "services.timesyncd.enable" is not set to "true", is commented out, or is missing, this is a finding.

Fix Text

Configure /etc/nixos/configuration.nix to regularly synchronize the system clock by adding the following configuration settings: services.timesyncd.enable = true; Rebuild the system with the following command: $ sudo nixos-rebuild switch

Additional Identifiers

Rule ID: SV-268151r1039341_rule

Vulnerability ID: V-268151

Group Title: SRG-OS-000356-GPOS-00144

Expert Comments

CCIs tied to check.

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