Mozilla Firefox before 15.0, Thunderbird before 15.0, and SeaMonkey before 2.12 do not prevent use of the Object.defineProperty method to shadow the location object (aka window.location), which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via vectors involving a plugin.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16367
https://bugzilla.mozilla.org/show_bug.cgi?id=756719
http://www.ubuntu.com/usn/USN-1548-2
http://www.ubuntu.com/usn/USN-1548-1
http://www.securityfocus.com/bid/55260
http://www.mozilla.org/security/announce/2012/mfsa2012-59.html
http://rhn.redhat.com/errata/RHSA-2012-1351.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