Mozilla Firefox before 31.0 does not properly restrict use of drag-and-drop events to spoof customization events, which allows remote attackers to alter the placement of UI icons via crafted JavaScript code that is encountered during (1) page, (2) panel, or (3) toolbar customization.
https://bugzilla.mozilla.org/show_bug.cgi?id=1000514
https://bugzilla.mozilla.org/show_bug.cgi?id=910375
http://secunia.com/advisories/59760
http://secunia.com/advisories/60628
https://security.gentoo.org/glsa/201504-01
http://www.mozilla.org/security/announce/2014/mfsa2014-60.html
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html