The Shell component in Android 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-08-01 does not properly manage the MANAGE_USERS and CREATE_USERS permissions, which allows attackers to bypass intended access restrictions via a crafted application, aka internal bug 29189712.
https://android.googlesource.com/platform/frameworks/base/+/4e4743a354e26467318b437892a9980eb9b8328a
https://android.googlesource.com/platform/frameworks/base/+/01875b0274e74f97edf6b0d5c92de822e0555d03