The debugger in the developer-tools subsystem in Mozilla Firefox before 15.0, when remote debugging is disabled, does not properly restrict access to the remote-debugging service, which allows remote attackers to execute arbitrary code by leveraging the presence of the HTTPMonitor extension and connecting to that service through the HTTPMonitor port.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17039
https://bugzilla.mozilla.org/show_bug.cgi?id=757128
http://www.ubuntu.com/usn/USN-1548-2
http://www.ubuntu.com/usn/USN-1548-1
http://www.securityfocus.com/bid/55308
http://www.mozilla.org/security/announce/2012/mfsa2012-66.html
http://lists.opensuse.org/opensuse-security-announce/2012-09/msg00014.html
http://lists.opensuse.org/opensuse-security-announce/2012-09/msg00011.html
http://lists.opensuse.org/opensuse-security-announce/2012-08/msg00028.html