The host is installed with Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbird before 16.0, Thunderbird ESR 10.x before 10.0.8 or SeaMonkey before 2.13 and is prone to use-after-free vulnerability. A flaw is present in the applications, which fail to properly handle vectors involving use of mozRequestFullScreen to enter full-screen mode, and use of the history.back method for backwards history navigation. Successful exploitation could allow attackers to execute arbitrary code.