usb-creator-helper in usb-creator before 0.2.28.3 does not enforce intended PolicyKit restrictions, which allows local users to perform arbitrary unmount operations via the UnmountFile method in a dbus-send command.
https://launchpad.net/bugs/771553
https://exchange.xforce.ibmcloud.com/vulnerabilities/67241
http://www.vupen.com/english/advisories/2011/1143
http://www.ubuntu.com/usn/usn-1127-1/