CVE-2019-11757

Siguiendo la cadena de prototipos de valor, era posible retener una referencia a una configuración regional, eliminarla y, posteriormente, hacer referencia a ella. Esto resultó en un uso de la memoria previamente liberada y un bloqueo explotable potencialmente. Esta vulnerabilidad afecta a Firefox versiones anteriores a la versión 70, Thunderbird versiones anteriores a la versión 68.2 y Firefox ESR versiones anteriores a la versión 68.2.

A use-after-free flaw was found in Mozilla Firefox and Thunderbird. When following a value's prototype chain, it was possible to retain a reference to a locale, delete it, and subsequently reference it. An attacker could use this flaw to execute code that was stored in the referenced memory or crash the system.

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 security restrictions, bypass same-origin restrictions, conduct cross-site scripting attacks, or execute arbitrary code. Various other issues were also addressed.