SAMS Teach Yourself Red Hat® Fedora™ 4 Linux® All in One

Logging Users Out Automatically

It is not uncommon for a user to log in to her account on a Linux system and to then become preoccupied with some other task or situation, forgetting that she is logged in at all. The user's session then sits inactive for an extended period of time.

Unfortunately, inactive user sessions can represent a serious security risk, especially on systems that allow remote logins. Network connections that are left open this way can eventually be hijacked by malicious users, who then have access to the user's account and, by extension, your system.

Aside from the religious use of ssh in place of telnet or other remote login commands, this type of risk can most easily be remedied by setting a login timeout—a delay after which ...