Mozilla Firefox before 34.0, Firefox ESR 31.x before 31.3, Thunderbird before 31.3, and SeaMonkey before 2.31 might allow remote attackers to execute arbitrary code by leveraging an incorrect cast from the BasicThebesLayer data type to the BasicContainerLayer data type.
Exploitability
AV:NAC:MAu:NImpact
C:PI:PA:P6.8/AV:N/AC:M/Au:N/C:P/I:P/A:P