usb-creator before 0.2.38.3ubuntu0.1 on Ubuntu 12.04 LTS, before 0.2.56.3ubuntu0.1 on Ubuntu 14.04 LTS, before 0.2.62ubuntu0.3 on Ubuntu 14.10, and before 0.2.67ubuntu0.1 on Ubuntu 15.04 allows local users to gain privileges by leveraging a missing call checkpolkit for the KVMTest method.
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.