This document is a general overview of security issues that face the administrator of Linux systems. It covers general security philosophy and a number of specific examples of how to better secure your Linux system from intruders. Also included are pointers to security related material and programs. NOTE: This is a beta version of this document. Improvements, constructive criticism, additions and corrections are gratefully accepted. Please mail your feedback to both authors. Be sure and include "Linux", "security" or "HOWTO" in the subject line of your mail to avoid spam filters and to bring your mail to the quick attention of the authors.