CVE-2011-1347

Vulnerabilidad sin especificar en Microsoft Internet Explorer 8 en Windows 7 permite a atacantes remotos evitar el modo protegido ("Protected Mode") y crear archivos arbitrarios utilizando el acceso a un proceso de baja integridad, como ha demostrado Stephen Fewer en una de las tres vulnerabilidades encadenadas durante el concurso Pwn2Own y CanSecWest 2011.

This vulnerability allows remote attackers to escape Protected Mode on vulnerable installations of Internet Explorer.
Internet Explorer Protected Mode consists of a Medium Integrity and a Low Integrity process. The Low Integrity process is only allowed to write to special Low Integrity locations. File written there are marked as Low Integrity files. When a new Internet Explorer process is launched it checks the Integrity of the file it is launched against. If the file is a Low Integrity file it will run the process in Low Integrity Mode. It is however possible to give the file an even lower permission: Untrusted, since this does not match the check for 'Low Integrity' the Internet Explorer will run in Medium Integrity instead of Low Integrity. This can be abused in an exploit to bypass the Protected Mode design and thus allow an attacker to escalate their privileges.