The protocol-handler dialog in Mozilla Firefox before 44.0 allows remote attackers to conduct clickjacking attacks via a crafted web site that triggers a single-click action in a situation where a double-click action was intended.
lists.opensuse.org/opensuse-security-announce/2016-02/msg00001.html
lists.opensuse.org/opensuse-security-announce/2016-02/msg00002.html
www.mozilla.org/security/announce/2016/mfsa2016-06.html
www.securityfocus.com/bid/81957
www.securitytracker.com/id/1034825
www.ubuntu.com/usn/USN-2880-1
www.ubuntu.com/usn/USN-2880-2
bugzilla.mozilla.org/show_bug.cgi?id=724353
security.gentoo.org/glsa/201605-06