Mozilla Firefox before 16.0.2, Firefox ESR 10.x before 10.0.10, Thunderbird before 16.0.2, Thunderbird ESR 10.x before 10.0.10, and SeaMonkey before 2.13.2 do not prevent use of the valueOf 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%3A16918
http://www.ubuntu.com/usn/USN-1620-2
http://www.ubuntu.com/usn/USN-1620-1
http://www.securityfocus.com/bid/56301
http://www.mozilla.org/security/announce/2012/mfsa2012-90.html
http://secunia.com/advisories/55318
http://secunia.com/advisories/51165
http://secunia.com/advisories/51147
http://secunia.com/advisories/51146
http://secunia.com/advisories/51144
http://secunia.com/advisories/51127
http://secunia.com/advisories/51123
http://secunia.com/advisories/51121
http://rhn.redhat.com/errata/RHSA-2012-1413.html
http://rhn.redhat.com/errata/RHSA-2012-1407.html
http://lists.opensuse.org/opensuse-security-announce/2012-10/msg00025.html
http://lists.opensuse.org/opensuse-security-announce/2012-10/msg00019.html