CVE-2019-11761

Mediante el uso de un formulario con un URI de datos, fue posible conseguir acceso al objeto JSONView privilegiado que había sido clonado en contenido. El impacto de exponer este objeto parece ser mínimo, sin embargo, fue una omisión de los mecanismos de defensa existentes en profundidad. 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 vulnerability was found in Mozilla Firefox and Thunderbird. Privileged JSONView objects that have been cloned into content can be accessed using a form with a data URI. This flaw bypasses existing defense-in-depth mechanisms and can be exploited over the network.

USN-4202-1 fixed vulnerabilities in Thunderbird. After upgrading, Thunderbird created a new profile for some users. This update fixes the problem. It was discovered that a specially crafted S/MIME message with an inner encryption layer could be displayed as having a valid signature in some circumstances, even if the signer had no access to the encrypted message. An attacker could potentially exploit this to spoof the message author. 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, bypass security restrictions, bypass same-origin restrictions, conduct cross-site scripting attacks, or execute arbitrary code. A heap overflow was discovered in the expat library in Thunderbird. If a user were tricked in to opening a specially crafted message, an attacker could potentially exploit this to cause a denial of service, or execute arbitrary code.