Multiple unspecified vulnerabilities in Google Chrome OS before 21.0.1180.50 on the Cr-48 and Samsung Series 5 and 5 550 Chromebook platforms, and the Samsung Chromebox Series 3, have unknown impact and attack vectors.
https://exchange.xforce.ibmcloud.com/vulnerabilities/77191
http://googlechromereleases.blogspot.com/2012/07/beta-channel-update-for-chrome-os.html