4.1.4 Ensure events that modify date and time information are collected - 'auditctl adjtimex'

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

For 32 bit systems add the following lines to the /etc/audit/audit.rules file:
-a always,exit -F arch=b32 -S adjtimex -S settimeofday -S stime -k time-change
-a always,exit -F arch=b32 -S clock_settime -k time-change
-w /etc/localtime -p wa -k time-change
For 64 bit systems add the following lines to the /etc/audit/audit.rules file:
-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

See Also

https://workbench.cisecurity.org/files/1866

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-12c., CSCv6|3.6

Plugin: Unix

Control ID: a1700fe5252b94455bfa4caf816513dbcda1683ca80c233de26e515bffa92c5b