The host is installed with Mozilla Firefox before 34.0, Firefox ESR 31.x before 31.3, Thunderbird before 31.3 or SeaMonkey before 2.31 and is prone to an arbitrary code execution vulnerability. A flaw is present in the applications, which fail to handle unknown vectors. Successful exploitation allows attackers to execute arbitrary code by leveraging an incorrect cast from the BasicThebesLayer data type to the BasicContainerLayer data type.