Apple didn’t bother with getting things fixed that quickly, so Mozilla has jumped on the ball and updated Firefox to version 2.0.0.7 to fix the recent QuickTime vulnerability. If your Firefox hasn’t updated itself – then it should soon (or you can always go to Help > Check for Updates to get the latest Firefox version).
Need more? Here is a little more information about this issue and fix via Mozilla Developer News:
Due to the security fixes, [...]