CVE-2017-5448

Escritura fuera de límites en "ClearKeyDecryptor" mientras se descodifican algunos contenidos multimedia cifrados mediante Clearkey. El código "ClearKeyDecryptor" se ejecuta en el sandbox Gecko Media Plugin (GMP). Si se descubre que un segundo mecanismo escapa del sandbox, esta vulnerabilidad permite la escritura de datos arbitrarios en la memoria, lo que resulta en un cierre inesperado potencialmente explotable. La vulnerabilidad afecta a Firefox ESR en versiones anteriores a la 45.9, Firefox ESR en versiones anteriores a la 52.1 y Firefox en versiones anteriores a la 53.

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Mozilla Firefox. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the handling of ClearKey encrypted media. The issue results from the lack of proper validation of user-supplied data, which can result in an integer overflow before writing to memory. An attacker can leverage this vulnerability to execute arbitrary code under the context of the plugin-container container process.

USN-3260-1 fixed vulnerabilities in Firefox. The update caused the date picker panel and form validation errors to close immediately on opening. 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, spoof the addressbar contents or other UI elements, escape the sandbox to read local files, conduct cross-site scripting attacks, cause a denial of service via application crash, or execute arbitrary code. A flaw was discovered in the DRBG number generation in NSS. If an attacker were able to perform a man-in-the-middle attack, this flaw could potentially be exploited to view sensitive information. Various other issues were also addressed.