Linux® on the Mainframe

8.3. Before opening the doors: hardening

A process sometimes used in the UNIX and Linux community is hardening. A “hardened” system is presumed to be impervious to any currently known attacks, exposures, or vulnerabilities. Every system, Linux or otherwise, should be hardened before being placed on any active LAN. Hardening is not a one-time task. Depending on the level of acceptable risk, triggers must be identified to ensure that the system configuration is revisited as needed. The security policy should contain criteria that trigger a reassessment of the configuration. For example, if a new Internet worm is identified and is known to attack the e-mail server, the security policy must be checked, and systems must be updated and rehardened. ...