Wietse Venema, the developer of Postfix, points in an advisory to a security problem in connection with the Linux and Solaris filesystems. As more recent versions of these operating systems no longer comply with the POSIX standard for links, local attackers may be able to attach files to other users' Postfix mailboxes.

Mozilla has just released version 3.0.1 of the Firefox browser; the first maintenance update removes a couple of vulnerabilities and fixes a some minor bugs.

Argus helps you monitor the flow of data on your network, detect trends, discover worms and viruses, and analyze bandwidth usage.

A tarpit slows down spam by reducing the effectiveness of the spammer’s weapons.

Spam filters can help smooth the waves in your inbox, as long as they are reliable and don’t have too many side effects. We’ll show you what we found when we tested five antispam appliances and two service providers.

We’ll show you a custom solution for moving spam to a separate folder and adding new spam signatures to SpamAssassin.

Track down and expose intruders with the versatile admin tool lsof.

Backdoors give attackers unrestricted access to a zombie system. If you plan to stop the bad guys from settling in, you’ll be interested in this analysis of the tools they might use for building a private entrance.