Unspecified vulnerability in Microsoft Internet Explorer 10 on Windows 8 allows remote attackers to bypass the sandbox protection mechanism by leveraging access to a Medium integrity process, as demonstrated by VUPEN during a Pwn2Own competition at CanSecWest 2013.
http://twitter.com/thezdi/statuses/309452625173176320
http://twitter.com/VUPEN/statuses/309479075385327617
http://h30499.www3.hp.com/t5/HP-Security-Research-Blog/Pwn2Own-2013/ba-p/5981157