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.
lists.opensuse.org/opensuse-security-announce/2012-08/msg00028.html
lists.opensuse.org/opensuse-security-announce/2012-09/msg00011.html
lists.opensuse.org/opensuse-security-announce/2012-09/msg00014.html
rhn.redhat.com/errata/RHSA-2012-1351.html
www.mozilla.org/security/announce/2012/mfsa2012-59.html
www.securityfocus.com/bid/55260
www.ubuntu.com/usn/USN-1548-1
www.ubuntu.com/usn/USN-1548-2
bugzilla.mozilla.org/show_bug.cgi?id=756719
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16367