CVE-2011-1290

Un desbordamiento de enteros en WebKit, tal y como es usado en el BlackBerry Torch 9800 de Research In Motion (RIM) con versión de firmware 6.0.0.246, en Google Chrome anterior a versión 10.0.648.133 y en Apple Safari anterior a versión 5.0.5, permite a los atacantes remotos ejecutar código arbitrario por medio de vectores desconocidos relacionados a el "style handling," de CSS, los ajustes de nodos y un valor de longitud, como es demostrado por Vincenzo Iozzo, Willem Pinckaers y Ralf-Philipp Weinmann durante una competencia de Pwn2Own en CanSecWest 2011.

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Webkit. 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 WebKit library's implementation of a CSS style. When totaling the length of it's string elements, the library will store the result into a 32bit integer. This value will be used for an allocation and then later will be used to initialize the allocated buffer. Due to the number of elements being totaled being variable, this will allow an aggressor to provide as many elements as necessary in order to cause the integer value to wrap causing an under-allocation. Initialization of this data will then cause a heap-based buffer overflow. This can lead to code execution under the context of the application.