MS confirms 'F1 to pwn' IE bug

Microsoft has confirmed that an unpatched Internet Explorer vulnerability makes it potentially dangerous to press F1 if you are running earlier versions of Windows.

A security bug in the VBScript technology bundled with Internet Explorer means that it might be possible to create a web site that displays a specially crafted dialog box that pushes malware providing a victim is tricked into pressing the F1 (help menu) key while viewing a booby-trapped site using Internet Explorer. The novel exploit technique works on older versions of Windows (Win 2000, XP and Server 2003). As previously reported, Vista, Windows 7 and Windows Server 2008 are immune.

Proof of concept code is reportedly in circulation but Microsoft said: “We are not aware of attacks that try to use the reported vulnerabilities or of customer impact at this time.”

Redmond went on to criticise security researchers for not coming to them with the problem first in an advisory, published on Monday.

“Microsoft is concerned that this new report of a vulnerability was not responsibly disclosed, potentially putting computer users at risk. We continue to encourage responsible disclosure of vulnerabilities. We believe the commonly accepted practice of reporting vulnerabilities directly to a vendor serves everyone's best interests. This practice helps to ensure that customers receive comprehensive, high-quality updates for security vulnerabilities without exposure to malicious attackers while the update is being developed.”

The advisory expands on an earlier holding statement in providing a list of potentially vulnerable systems, a preliminary risk assessment and suggested workarounds. Redmond security gnomes are still investigating the flaw but a decision to develop a patch looks like a big odds-on favourite if past form holds true.

Microsoft gave no indication of when a patch might become available but the next scheduled Patch Tuesday is only six days away, cutting it very fine to develop, much less test, a fix. An April or even May update for IE seems more likely. ®