Information
ntp is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on NTP can be found at http://www.ntp.org. ntp can be configured to be a client and/or a server.
This recommendation only applies if ntp is in use on the system.
Rationale:
If ntp is in use on the system proper configuration is vital to ensuring time synchronization is working properly.
Solution
Add or edit restrict lines in /etc/ntp.conf to match the following:
restrict -4 default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
Add or edit server or pool lines to /etc/ntp.conf as appropriate:
Example vim /etc/ntp.conf
server <remote-server>
Configure ntp to run as the ntp user by adding or editing one of the following file:
/etc/sysconfig/ntpd :
OPTIONS='-u ntp:ntp'
Notes:
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