MEDIUM
Mozilla Firefox before 42.0 on Android does not ensure that the address bar is restored upon fullscreen-mode exit, which allows remote attackers to spoof the address bar via crafted JavaScript code.
http://lists.opensuse.org/opensuse-security-announce/2015-11/msg00015.html
http://www.mozilla.org/security/announce/2015/mfsa2015-119.html
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html