F-Secure patches antivirus software

Company issues fix for a wide range of its products

Antivirus software vendor F-Secure Corp. issued a patch for a wide range of its products Thursday after a security researcher in Luxembourg reported vulnerabilities to the company.

A flaw in the way F-Secure software handled ZIP and RAR format data compression archives could allow an attacker to execute remote code on users' systems and to bypass F-Secure's antivirus-scanning capabilities, according to Thierry Zoller, the security engineer and penetration tester who reported the vulnerability to F-Secure. F-Secure called the vulnerability "critical."

F-Secure customers received an automated hot fix early Thursday morning California time, the same time as the company published the vulnerability, said David Frazer, senior project manager for F-Secure. "There was no user interaction required," Frazer said.

"Millions" of F-Secure customers used the software affected by the flaws, Frazer said. "As far as we know, the vulnerability has not been exploited," he said. "When you have a vulnerability of a critical nature, you want to get a hot fix out before somebody has a chance to exploit it."

The "vast majority" of F-Secure's antivirus product line, including F-Secure Anti-Virus for Windows Servers versions 5.52 and earlier and F-Secure Anti-Virus for Workstations 5.44 and earlier, were affected by the vulnerability, Frazer said. Antivirus scanners for Linux, Samba and firewalls were also affected.

The company uses the same antivirus engine in most of its product line, Frazer said. "It was the same vulnerability in all of the product series," he added.

Zoller, on his blog, praised F-Secure for publicly fixing the vulnerability. "I found multiple vulnerabilities within various [antivirus] Engines, F-Secure are the first to actually publish a real advisory, others fixed the bugs silently or put a small notice in a change_log," he wrote.

Zoller said he will wait to publish details of the vulnerability. "There are too many [anitvirus] engines vulnerable and I am going to wait until most of them have patched the flaws until I exactly disclose my findings," he wrote.

Copyright © 2006 IDG Communications, Inc.