Multiple Mozilla products contain a flaw that allows a remote cross-site scripting (XSS) attack. This flaw exists because the application does not validate input passed via the displayed url when an attacker exploits a flaw in docshell's page loading which allows for the manipulation of the displayed URL, which may allow for manipulation of the displayed URL. This may allow a user to create a specially crafted URL that would execute arbitrary script code in a user's browser within the trust relationship between their browser and the server.
Remote / Network Access,
Loss of Integrity
Upgrade Firefox and Thunderbird to version 12.0 or higher (10.0.4 for ESR) and SeaMonkey to version 2.9 or higher, as they have been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.