Vulnerability Discussion
Approved time servers must be the only servers configured for use.
This rule ensures the uniformity of time stamps for information systems with multiple system clocks and systems connected over a network.
An authoritative time server is synchronized with redundant United States Naval Observatory (USNO) time servers as designated for the appropriate DOD network.
Satisfies: SRG-OS-000355-GPOS-00143,SRG-OS-000356-GPOS-00144
Check
Verify the macOS system is configured to use an authorized time server with the following command:
/usr/bin/osascript -l JavaScript << EOS
$.NSUserDefaults.alloc.initWithSuiteName('com.apple.MCX')\
.objectForKey('timeServer').js
EOS
If the result is not an authoritative time server which is synchronized with redundant USNO time servers as designated for the appropriate DOD network, this is a finding.
Fix
Configure the macOS system to use an authorized time server by installing the "com.apple.MCX" configuration profile.