IBM AIX SECURITY POLICY - Enforcing automatic logoff

Enable automatic logoff to prevent an intruder from compromising the security of the system.

Another valid security concern results from users leaving their accounts unattended for a lengthy period of time. This situation allows an intruder to take control of the user's terminal, potentially compromising the security of the system.

To prevent this type of potential security hazard, you can enable automatic logoff on the system. To do this, edit the /etc/security/.profile file to include an automatic logoff value for all users, as in the following example:

TMOUT=600; TIMEOUT=600; export TMOUT TIMEOUT; readonly TMOUT TIMEOUT

The number 600, in this example, is in seconds, which is equal to 10 minutes. However, this method will only work from the shell.

While the previous action allows you to enforce an automatic logoff policy for all users, system users can bypass some restrictions by editing their individual .profile files. To completely implement an automatic logoff policy, take authoritative action by providing users with appropriate .profile files, preventing write-access rights to these files.