[ Thanks to BeOpen
for this link. ]
“Linux, despite its incredible stability, is insecure in its
generally distributed form. Almost all major distributions –
including Red Hat, Corel, Caldera, Debian, SuSE, TurboLinux, and
others – have major unpatched vulnerabilities. Staying on top of
security alerts for your distribution is one half of keeping your
system secure. Using the patches that are released with these
security alerts will make your system less vulnerable than it was
before, however it does not solve the problem as a whole. The main
security problem with Linux is its constantly running system
services and daemons, such as httpd (Apache), inetd, sendmail, and
others. In order to secure a system to the greatest extent
possible, you must first assess what daemons are vital to the
system’s function. For example, if you are running an anonymous FTP
server, you will not want Telnet or HTTP services running on that
machine. This tutorial will discuss the importance of choosing
system services, look at file permissions, and take a brief look at
Tripwire for system analysis.”
“System services are the core security problem on most Linux
systems. By default, most Linux distributions have systems running
almost every service available to the system at startup. This is a
major problem, but you can fix it. The first step is to assess what
your computer is expected to do; whether you want it to be an FTP,
Web, shell, or other type of server. After you have decided this,
you must then determine which system services and daemons are
running on your system….”