Risk: Medium
Crackers are using a security vulnerability in Symantec's enterprise products to redirect surfers to web sites hosting malicious code. The main vector of the DNS cache poisoning attack, detected by the SANS Institute's Internet Storm Centre, has been traced back to a vulnerability affecting Symantec firewalls with DNS caching.
Symantec has issued a hotfix for its Symantec Enterprise Firewall and Enterprise Security Gateway appliance products. Even users who applied a July 2004 fix to correct a previous DNS cache-poisoning problem are advised to revisit the issue. A few non-Symantec users reported similar issues, so the problem is not solely confined to the Symantec firewall. The SANS Institute, which is tracking the issue, has issued general advice on dealing with the problem.
As a result of the attack, enterprise users visiting popular domain names such as google.com, ebay.com, and weather.com were redirected to servers hosting malware (the ABX toolbar spyware). The spyware was loaded using an ActiveX-control, blocked by XP SP2, but other Windows shops will have to clean up client machines as well as patch enterprise systems.