CVE-2016-5259

Vulnerabilidad de uso después de liberación de memoria en la función CanonicalizeXPCOMParticipant en Mozilla Firefox en versiones anteriores a 48.0 y Firefox ESR 45.x en versiones anteriores a 45.3 permite a atacantes remotos ejecutar código arbitrario a través de una secuencia de comandos que cierra su propio Service Worker dentro de un bloque de eventos sync anidados.

Gustavo Grieco discovered an out-of-bounds read during XML parsing in some circumstances. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit this to cause a denial of service via application crash, or obtain sensitive information. Toni Huttunen discovered that once a favicon is requested from a site, the remote server can keep the network connection open even after the page is closed. A remote attacker could potentially exploit this to track users, resulting in information disclosure. Various other issues were also addressed.