server/content/SyncStorageEngine.java in SyncStorageEngine in Android 4.x before 4.4.4 5.0.x before 5.0.2 5.1.x before 5.1.1 and 6.x before 2016-04-01 mismanages certain authority data which allows attackers to cause a denial of service (reboot loop) via a crafted application aka internal bug 26513719.