CVE-2017-7805

Durante los intercambios TLS 1.2, los hashes de los handshakes se generan apuntando a un búfer de mensaje. Estos datos guardados se utilizan para futuros mensajes pero, en determinados casos, la transcripción del handshake puede exceder el espacio disponible en el búfer actual, provocando la asignación de un nuevo búfer. Esto deja al puntero apuntando al búfer antiguo liberado, resultando en una condición de uso de memoria previamente liberada cuando los hashes del handshake se calculan posteriormente. Esto puede resultar en un cierre inesperado explotable. Esta vulnerabilidad afecta a las versiones anteriores a la 56 de Firefox, las versiones anteriores a la 52.4 de Firefox ESR y las versiones anteriores a la 52.4 de Thunderbird.

A use-after-free flaw was found in the TLS 1.2 implementation in the NSS library when client authentication was used. A malicious client could use this flaw to cause an application compiled against NSS to crash or, potentially, execute arbitrary code with the permission of the user running the application.

USN-3435-1 fixed vulnerabilities in Firefox. The update caused the Flash plugin to crash in some circumstances. This update fixes the problem. Multiple security issues were discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could potentially exploit these to read uninitialized memory, obtain sensitive information, bypass phishing and malware protection, spoof the origin in modal dialogs, conduct cross-site scripting attacks, cause a denial of service via application crash, or execute arbitrary code. Martin Thomson discovered that NSS incorrectly generated handshake hashes. A remote attacker could potentially exploit this to cause a denial of service via application crash, or execute arbitrary code. Multiple security issues were discovered in WebExtensions. If a user were tricked in to installing a specially crafted extension, an attacker could potentially exploit these to download and open non-executable files without interaction, or obtain elevated privileges. Various other issues were also addressed.