CVE-2020-6819

Bajo determinadas condiciones, cuando se ejecuta el destructor nsDocShell, una condición de carrera puede causar un uso de la memoria previamente liberada. Somos conscientes de los ataques dirigidos "in the wild" que abusan de este fallo. Esta vulnerabilidad afecta a Thunderbird versiones anteriores a 68.7.0, Firefox versiones anteriores a 74.0.1 y Firefox ESR versiones anteriores a 68.6.1.

A flaw was found in Mozilla Firefox. A race condition can occur while running the nsDocShell destructor causing a use-after-free memory issue. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

It was discovered that Message ID calculation was based on uninitialized data. An attacker could potentially exploit this to obtain sensitive information. Multiple security issues were discovered in Thunderbird. If a user were tricked in to opening a specially crafted message, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, or execute arbitrary code. Various other issues were also addressed.

Mozilla Firefox and Thunderbird contain a race condition vulnerability when running the nsDocShell destructor under certain conditions. The race condition creates a use-after-free vulnerability, causing unspecified impacts.