CVE-2017-5428

Se ha informado acerca de un desbordamiento de enteros en "createImageBitmap()" a través del concurso Pwn2Own. La solución para esta vulnerabilidad deshabilita las extensiones experimentales a la API "createImageBitmap". Esta función se ejecuta en el sandbox de contenido, siendo necesaria una segunda vulnerabilidad para comprometer el ordenador de un usuario. La vulnerabilidad afecta a Firefox ESR en versiones anteriores a la 52.0.1 y Firefox en versiones anteriores a la 52.0.1.

A flaw was found in the processing of malformed web content. A web page containing malicious content could cause Firefox to crash or, potentially, execute arbitrary code with the privileges of the user running Firefox.

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 createImageBitmap. 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 current user.