Three unpatched flaws in Internet Explorer now pose a higher danger, a security company warned, after code to exploit one of the issues was published to the Internet. Secunia said Friday that it had raised its rating of the vulnerabilities in Microsoft's browser to "extremely critical," its highest rating. The flaws, which affect IE 6, could enable attackers to place and execute programs such as spyware and pornography dialers on victims' computers without their knowledge, said Thomas Kristensen, Secunia's chief technology officer.


Exploit code for one of the vulnerabilities, a flaw in an HTML Help control, was published on the Internet on Dec. 21 in an advisory by GreyHats Security Group.

"In order for us to rate a vulnerability as extremely critical, there has to be a working exploit out there and one that doesn't require user interaction," Kristensen said. "This is our highest rating and is the last warning for users to fix their systems."

The exploit code can be used to attack computers running Windows XP even if Microsoft's Service Pack 2 patch has been installed, Secunia said. The company is advising people to disable IE's Active X support as a preventative measure, until Microsoft develops a patch for the problem. It also suggests using another browser product.