The (1) IsVolumeAccessibleByCurrentUser and (2) MountDevice methods in Ntdriver.c in TrueCrypt 7.0, VeraCrypt before 1.15, and CipherShed, when running on Windows, do not check the impersonation level of impersonation tokens, which allows local users to impersonate a user at SecurityIdentify level and gain access to other users' mounted encrypted volumes.
https://veracrypt.codeplex.com/wikipage?title=Release%20Notes
https://code.google.com/p/google-security-research/issues/detail?id=537
http://www.openwall.com/lists/oss-security/2015/09/24/3
http://www.openwall.com/lists/oss-security/2015/09/22/7
http://packetstormsecurity.com/files/133877/Truecrypt-7-Privilege-Escalation.html