The vulnerability was described as a "memory safety problem in the array.join function" and was bundled into a security advisory that carries a critical rating.
Even before a pair of researchers hacked into Firefox to snag second place at the CanSecWest Pwn2Own contest, Mozilla knew about the vulnerability and was working on a fix.
That fix arrived today with Firefox 11, a high-priority update that fixes a dozen security flaws that expose Windows and Mac OS X users to a wide range of hacker attacks.
"The security bug reported by ZDI is one we had already identified and fixed through our internal processes," said Johnathan Nightingale, Senior Director of Firefox Engineering.
Mozilla had originally delayed the release of Firefox 11 to wait for the Pwn2Own vulnerability details but once the open-source group realized it was the same issue that was identified by researcher Jeff Walden, the patch was pushed out the door.
The vulnerability was described as a "memory safety problem in the array.join function" and was bundled into a security advisory that carries a critical rating. At Pwn2Own, researchers Willem Pinckaers and Vincenzo Iozzo exploited the flaw to launch a remote code execution attack that required no user action beyond browsing to a rigged web page.