CVE-2012-3993

La implementación Chrome Object Wrapper (COW) en Mozilla Firefox v16.0, Firefox ESR v10.x antes de v10.0.8, Thunderbird antes de v16.0, Thunderbird ESR v10.x antes de v10.0.8, y SeaMonkey antes de v2.13, no interactúa apropiadamente con fallos de métodos de InstallTrigger, lo que permite a atacantes remotos ejecutar código JavaScript de su elección con privilegios chrome a través de una página web modificada, relacionada con un problema "XrayWrapper pollution"

On versions of Firefox from 5.0 to 15.0.1, the InstallTrigger global, when given invalid input, would throw an exception that did not have an __exposedProps__ property set. By re-setting this property on the exception object's prototype, the chrome-based defineProperty method is made available. With the defineProperty method, functions belonging to window and document can be overriden with a function that gets called from chrome-privileged context. From here, another vulnerability in the crypto.generateCRMFRequest function is used to "peek" into the context's private scope. Since the window does not have a chrome:// URL, the insecure parts of Components.classes are not available, so instead the AddonManager API is invoked to silently install a malicious plugin.