browser/extensions/api/tabs/tabs_api.cc in Google Chrome before 28.0.1500.71 does not properly enforce restrictions on the capture of screenshots by extensions, which allows remote attackers to obtain sensitive information about the content of a previous page via vectors involving an interstitial page.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17350
https://code.google.com/p/chromium/issues/detail?id=229504
http://www.debian.org/security/2013/dsa-2724
http://googlechromereleases.blogspot.com/2013/07/stable-channel-update.html