InformationFor networked systems, the operating system must synchronize clocks with a server that is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, a time server designated for the appropriate DoD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS).
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).
SolutionEdit the /etc/ntp.conf file and add or update an entry to define maxpoll to 10 as follows:
Example: vim /etc/ntp.conf
Add the following line:
server 0.amazon.pool.ntp.org iburst maxpoll 10
If NTP was running and maxpoll was updated, the NTP service must be restarted:
# systemctl restart ntpd
If NTP was not running, it must be started:
# systemctl start ntpd
This Benchmark recommendation maps to:
Red Hat Enterprise Linux 7 Security Technical Implementation Guide:
Version 2, Release: 3 Benchmark Date: 26 Apr 2019
Vul ID: V-72269
Rule ID: SV-86893r4_rule
STIG ID: RHEL-07-040500
Severity: CAT II