VUPEN Security Research - Google Chrome Clipboard Format Processing
Sandbox Escape (Pwn2Own)

Website : https://www.vupen.com

Twitter : https://twitter.com/vupen


I. BACKGROUND
---------------------

"Google Chrome is a freeware web browser developed by Google. Chrome
version 28 and beyond uses the WebKit fork Blink. As of 2013,
StatCounter estimates that Google Chrome has a 39% worldwide usage
share of web browsers" (Wikipedia).


II. DESCRIPTION
---------------------

VUPEN Vulnerability Research Team discovered a critical vulnerability
in Google Chrome.

The vulnerability is caused by an input validation error within the
"Clipboard::WriteData()" function that does not restrict the value of
the "format" parameter, which could be exploited to escape Chrome's
sandbox and achieve code execution with Medium integrity level.


III. AFFECTED PRODUCTS
---------------------------

Google Chrome versions prior to 33.0.1750.154


IV. SOLUTION
----------------

Upgrade to Chrome version version 33.0.1750.154.


V. CREDIT
--------------

This vulnerability was discovered by VUPEN Security.


VI. ABOUT VUPEN Security
---------------------------

VUPEN is the leading provider of defensive and offensive cyber security
intelligence and advanced zero-day research. All VUPEN's vulnerability
intelligence results exclusively from its internal and in-house R&D
efforts conducted by its team of world-class researchers.

VUPEN Solutions: https://www.vupen.com/english/services/


VII. REFERENCES
----------------------

https://googlechromereleases.blogspot.com/2014/03/stable-channel-update_14.html


VIII. DISCLOSURE TIMELINE
-----------------------------

2013-12-19 - Vulnerability Discovered by VUPEN Security
2014-03-13 - Vulnerability Reported to Google/ZDI During Pwn2Own 2014
2014-03-14 - Vulnerability Fixed by Google
2014-03-26 - Public disclosure