CVE-2020-35111

Cuando una extensión con el permiso de proxy se registró para recibir (all_urls), la devolución de llamada proxy.onRequest no se desencadenó para las URL de vista de origen. Si bien el contenido web no puede navegar a dichas URL, un usuario que abra View Source podría haber filtrado inadvertidamente su dirección IP. Esta vulnerabilidad afecta a Firefox versiones anteriores a 84, Thunderbird versiones anteriores a 78,6 y Firefox ESR versiones anteriores a 78,6

The Mozilla Foundation Security Advisory describes this flaw as: When an extension with the proxy permission registered to receive `<all_urls>`, the proxy.onRequest callback was not triggered for view-source URLs. While web content cannot navigate to such URLs, a user opening View Source could have inadvertently leaked their IP address.

Multiple security issues were discovered in Thunderbird. If a user were tricked in to opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, bypass the CSS sanitizer, or execute arbitrary code. It was discovered that the proxy.onRequest API did not catch view-source URLs. If a user were tricked in to installing an extension with the proxy permission and opening View Source, an attacker could potentially exploit this to obtain sensitive information. Various other issues were also addressed.