The image-codec implementation in the PDF functionality in Google Chrome before 20.0.1132.43 does not initialize an unspecified pointer, which allows remote attackers to cause a denial of service or possibly have unknown other impact via a crafted document.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A15455
http://googlechromereleases.blogspot.com/2012/06/stable-channel-update_26.html