Original URL: http://www.theregister.co.uk/2009/05/12/av_xss_six/

XSS flaws found in sites of multiple anti-virus firms

Dirty half-dozen

By John Leyden

Posted in Security, 12th May 2009 10:39 GMT

Security researchers have revealed that the websites of no less than six anti-virus firms are vulnerable to cross-site scripting flaws, of a type that might lend themselves to phishing attacks.

Some of the firms involved have admitted problems, while others say the issues raised have either already been fixed or are erroneous.

Nemesis, a gang of programmers and security bods that work mostly in chat room software development, reckons the sites of Symantec, Kaspersky, Eset (Nod32), AVG, F-secure and Trend Micro are all vulnerable, one way or another. The group has posted screen shots to back up its claims in an advisory here.

El Reg contacted the six firms involved on Monday evening, some of who have already got back to us. We'll add statements from the others as and when they become available.

Broadly speaking the cross-site scripting flaws detailed by the Nemesis make it possible to present rogue iFrames from third-party servers as if they came from the sites of security vendors a surfer might be visiting. This type of vulnerability therefore lends itself to attacks that rely on impersonation, such as phishing. XSS flaws, more generally, also pose cookie stealing and other risks.

This class of vulnerability has popped up on the website of security firms over recent months. Most notable Romanian hacking group HackersBlog exposed XSS flaws on the websites of Kaspersky, BitDefender, F-Secure and Symantec in a two month campaign before the group got bored and disbanded in late March 2009.

Other incidents of similar problems on the websites of McAfee and Symantec have cropped up since to the point where its tempting to think that the problem has become endemic.

In other security-related news, AVG released a fix for a vulnerability involving how its software processes Zip files. An advisory on the flaw, discovered by security researcher Thierry Zoller, can be found here. ®