17.3 Summary

Keeping your Unix system secure is an ongoing responsibility. Different systems and vendors have different strategies for distributing updates and bug fixes. You must find out how this information is distributed for your system, and you must keep up to date.

Be sure that you get your updates from a reliable source. After you have installed your updates, continue to monitor mailing lists and web sites to make sure that the updates themselves have not been compromised—there are a growing number of cases in which people have installed security updates that actually contained vulnerabilities or full-blown Trojan horses. Ultimately, vigilance is the only way to protect yourself and your computer.