.jar not treated as executable in Firefox 3.6 on Mac

.jar not treated as executable in Firefox 3.6 on Mac

Announced

December 20, 2011

Impact

Critical

Products

Firefox, Thunderbird

Fixed in

• Firefox 3.6.25
• Thunderbird 3.1.17

Description

Part of the fix for MFSA 2011-40, reported by Mariusz Mlynski, was to treat .jar files as executables. This is necessary because Java treats downloaded .jar files as fully-featured "Applications" rather than restricting them to the limited privileges of in-browser "Applets". The fix taken in Firefox 3.6 was discovered to be incorrect for the Mac OS X version.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=704622
• CVE-2011-3666