Mozilla Firefox before 41.0 allows remote attackers to bypass certain ECMAScript 5 (aka ES5) API protection mechanisms and modify immutable properties, and consequently execute arbitrary JavaScript code with chrome privileges, via a crafted web page that does not use ES5 APIs.
https://bugzilla.mozilla.org/show_bug.cgi?id=904886
http://www.ubuntu.com/usn/USN-2743-4
http://www.ubuntu.com/usn/USN-2743-3
http://www.ubuntu.com/usn/USN-2743-2
http://www.ubuntu.com/usn/USN-2743-1
http://www.securitytracker.com/id/1033640
http://www.securityfocus.com/bid/76815
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
http://www.mozilla.org/security/announce/2015/mfsa2015-109.html
http://lists.opensuse.org/opensuse-security-announce/2015-10/msg00005.html
http://lists.opensuse.org/opensuse-security-announce/2015-10/msg00000.html