CVE-2011-2378

La función appendChild en Firefox anterior a versión 3.6.20, Thunderbird versiones 3.x anteriores a 3.1.12, SeaMonkey versiones 2.x, y posiblemente otros productos de Mozilla, no maneja apropiadamente objetos DOM, lo que permite a los atacantes remotos ejecutar código arbitrario por medio de vectores no especificados que conlleva al desreferenciado de un "dangling pointer”

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Mozilla Firefox. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw results when .setUserData() handlers are used with an object and .appendChild() is called within a handler. Ultimately the import operation resulting from an .appendChild() is not guarded from mutation, and invalid DOM trees can result. Invalid DOM trees can be navigated resulting in dereferencing invalid pointers which can be leveraged to execute arbitrary code in the context of the browser.