CVE-2020-12420

Al intentar conectarse a un servidor STUN, una condición de carrera podría haber causado un uso de la memoria previamente liberada de un puntero, conllevando a una corrupción de la memoria y un bloqueo potencialmente explotable. Esta vulnerabilidad afecta a Firefox ESR versiones anteriores a 68.10, Firefox versiones anteriores a 78 y Thunderbird versiones anteriores a 68.10.0

The Mozilla Foundation Security Advisory describes this flaw as: When trying to connect to a STUN server, a race condition could have caused a use-after-free of a pointer, leading to memory corruption and a potentially exploitable crash.

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, or execute arbitrary code. It was discovered that Thunderbird would continue an unencrypted connection when configured to use STARTTLS for IMAP if the server responded with PREAUTH. A remote attacker could potentially exploit this to perform a person-in-the-middle attack in order to obtain sensitive information. Various other issues were also addressed.