Use-after-free vulnerability in the nsDocLoader::doStopDocumentLoad 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 or cause a denial of service (heap memory corruption) via vectors involving a state-change event during an update of the offline cache.