||Secure Your Linux Server|
|Subject:||The Bastille Hardening program as a starting point|
The Bastille Hardening program (http://www.bastille-linux.org/) is a great tool for towards hardening your Linux servers:
The Bastille Hardening program "locks down" an operating system, proactively configuring the system for increased security and decreasing its susceptibility to compromise. Bastille can also assess a system's current state of hardening, granularly reporting on each of the security settings with which it works.
Bastille currently supports the Red Hat (Fedora Core, Enterprise, and Numbered/Classic), SUSE, Debian, Gentoo, and Mandrake distributions, along with HP-UX and Mac OS X. Bastille's focuses on letting the system's user/administrator choose exactly how to harden the operating system. In its default hardening mode, it interactively asks the user questions, explains the topics of those questions, and builds a policy based on the user's answers. It then applies the policy to the system. In its assessment mode, it builds a report intended to teach the user about available security settings as well as inform the user as to which settings have been tightened.
I would recommend using the assessment mode on every server, even if you have not used Bastille to harden the system. You quickly learn what weaknesses the servers have, and even if a server in the green zone is not directly connected to the Internet, you will quickly discover where it could be exploited.