Unpatched QuickTime-to-Firefox flaw dings IE too

To demonstrate the attack scenario, Raff embedded a rigged QuickTime file on Google's BlogSpot to force a Skype shutdown if an IE user is tricked into visiting that Web page. Any limited Web environment that allows embedded QuickTime files can be used to host an attack against IE, Raff said.

This attack uses the same vulnerability disclosed earlier this week by Petko D. Petkov (pdp) that could be used to launch code execution attacks on Windows users if Firefox is set as the default browser.

[ GALLERY: How to run Internet Explorer securely ]

Raff is very familiar with this vulnerability. Earlier this year, during the Month of Apple Bugs project, Raff expanded on Petkov's earlier discovery and published an exploit (MOAB #3) to show how booby-trapped QuickTime files can remotely execute harmful code against Windows users.

Interestingly, Apple patched Raff's MOAB flaw with QuickTime 7.1.5 (even crediting the project in its advisory) but it's now clear that the fix was inadequate. "It wasn't fully fixed," Raff said, noting that QuickTime still allows protocol handlers from external Web sites.

[SEE: One-year-old QuickTime bug comes back to bite Firefox ] Apple does not respond to queries on specific security vulnerabilities.

The company has also been very tardy on supplying a fix for a code execution flaw in its Java runtime implementation. That flaw, rated critical by security experts, was first reported more than 10 months ago.