4.1.6 Ensure events that modify date and time information are collected - '/etc/localtime'

Information

Capture events where the system date and/or time has been modified. The parameters in this section are set to determine if the adjtimex (tune kernel clock), settimeofday (Set time, using timeval and timezone structures) stime (using seconds since 1/1/1970) or clock_settime (allows for the setting of several internal clocks and timers) system calls have been executed and always write an audit record to the /var/log/audit.log file upon exit, tagging the records with the identifier "time-change" Unexpected changes in system date and/or time could be a sign of malicious activity on the system.

Solution

Edit or create a file in the /etc/audit/rules.d/ directory ending in .rules Example: vi /etc/audit/rules.d/time-change.rules and add the following lines: -a always,exit -F arch=b64 -S adjtimex -S settimeofday -k time-change -a always,exit -F arch=b32 -S adjtimex -S settimeofday -S stime -k time- change -a always,exit -F arch=b64 -S clock_settime -k time-change -a always,exit -F arch=b32 -S clock_settime -k time-change -w /etc/localtime -p wa -k time-change Reloading the auditd config to set active settings may require a system reboot.

See Also

https://workbench.cisecurity.org/files/2608

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, CSCv7|5.5

Plugin: Unix

Control ID: dc0299169290227521f5e4aa0fbe97d5e572b158617fce4a64ad8098c6b7aaae