4.1.15 Ensure system administrator actions (sudolog) are collected

Information

Monitor the sudo log file. The sudo log file is configured in /etc/sudoers or a file in /etc/sudoers.d.

If the system has been properly configured to disable the use of the su command and force all administrators to have to log in first and then use sudo to execute privileged commands, then all administrator commands will be logged to to the sudo log file. Any time a command is executed, an audit event will be triggered as the sudo log file will be opened for write and the executed administration command will be written to the log.

Notes:

The system must be configured with su disabled (See Item 5.6 Ensure access to the su command is restricted) to force all command execution through sudo. This will not be effective on the console, as administrators can log in as root.

Reloading the auditd config to set active settings may require a system reboot.

Rationale:

Changes in /var/log/sudo.log indicate that an administrator has executed a command or the log file itself has been tampered with. Administrators will want to correlate the events written to the audit trail with the records written to /var/log/sudo.log to verify if unauthorized commands have been executed.

Solution

Edit or create a file in the /etc/audit/rules.d/ directory ending in .rules and add the following line:

-w <Path to sudo logfile> -p wa -k actions

Example: vi /etc/audit/rules.d/actions.rules
Add the following line:

-w /var/log/sudo.log -p wa -k actions

See Also

https://workbench.cisecurity.org/files/2925

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-3, CSCv7|4.9

Plugin: Unix

Control ID: 6d003fd01234fae88319f357a81fef0e8c335491cf0b7431fc811cdd14d61dea