NixOS must, for networked systems, compare internal information system clocks at least every 24 hours with a server which is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS).
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-268149 | ANIX-00-001420 | SV-268149r1039335_rule | CCI-004923 | medium |
| Description | ||||
| 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. Sources outside the configured acceptable allowance (drift) may be inaccurate. 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 endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). Satisfies: SRG-OS-000355-GPOS-00143, SRG-OS-000359-GPOS-00146, SRG-OS-000785-GPOS-00250 | ||||
| STIG | Date | |||
| Anduril NixOS Security Technical Implementation Guide | 2024-10-25 | |||
Details
Check Text (C-268149r1039335_chk)
Verify NixOS is configured with an approved time server with the following command:
$ timedatectl show-timesync | grep NTPServers
SystemNTPServers=tick.usnogps.navy.mil
FallbackNTPServers=tock.usnogps.navy.mil
If the output of the command does not list authorized time servers, this is a finding.
Fix Text (F-71976r1039334_fix)
Configure /etc/nixos/configuration.nix to use approved timeservers by adding the following configuration settings:
networking.timeServers = [
"tick.usnogps.navy.mil"
"tock.usnogps.navy.mil"
];
Rebuild the system with the following command:
$ sudo nixos-rebuild switch