Vulnerability Discussion

Without reauthentication, users may access resources or perform tasks for which they do not have authorization.

When operating systems provide the capability to escalate a functional capability, it is critical the organization requires the user to reauthenticate when using the "sudo" command.

If the value is set to an integer less than "0", the user's time stamp will not expire and the user will not have to reauthenticate for privileged actions until the user's session is terminated.

Check

Verify RHEL 9 requires reauthentication when using the "sudo" command to elevate privileges with the following command:

$ sudo grep -ir 'timestamp_timeout' /etc/sudoers /etc/sudoers.d/
/etc/sudoers:Defaults timestamp_timeout=0

If results are returned from more than one file location, this is a finding.

If "timestamp_timeout" is set to a value other than "0" (including negative numbers), is commented out, or is missing entirely, this is a finding.

Fix

Configure RHEL 9 to reauthenticate every invocation of the "sudo" command.

Add the following line to "/etc/sudoers" or a file in "/etc/sudoers.d":

Defaults timestamp_timeout=0

Remove any duplicate definitions.