The Security Mentor

One popular personal firewall program had a bug once. Someone wrote a worm which took advantage of the bug to install itself on every accessible computer running the buggy version. It did a lot of damage.

Security software has a problem. By definition it has to handle untrustworthy data. It's also a prime target for intruders.

Right now, according to Computerworld, almost all the popular antivirus software needs updates to cure vulnerabilities that would allow intruders to poison them or to turn them against you.

Worse, you likely won't get these updates automatically. Those automatic updates only bring you new data about what viruses to look for. Usually they don't update the program that does the looking.

Computerworld lists the following pages for more information and for updates:
F-Secure
McAfee
Symantec
Trend Micro