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 exists within the fix implemented for CVE-2010-2753 in the nsTreeSelection interface. In a certain condition, the application still can be made to free a reference and then made to use said freed reference. This can lead to code execution under the context of the application.