Launchpad.net

CVE 2013-1054

The unity-firefox-extension package could be tricked into destroying the Unity webapps context, causing Firefox to crash. This could be achieved by spinning the event loop inside the webapps initialization callback. Fixed in 3.0.0+14.04.20140416-0ubuntu1.14.04.1 by shipping an empty package, thus disabling the extension entirely.

See the CVE page on Mitre.org for more details.