Use-after-free vulnerability in the nsEventListenerManager::SetEventHandler function in Mozilla Firefox before 25.0 Firefox ESR 17.x before 17.0.10 and 24.x before 24.1 Thunderbird before 24.1 Thunderbird ESR 17.x before 17.0.10 and SeaMonkey before 2.22 allows remote attackers to execute arbitrary code via vectors related to a memory allocation through the garbage collection (GC) API.