systemui/statusbar/phone/QuickStatusBarHeader.java in the System UI Tuner in Android 7.0 before 2016-09-01 does not prevent tuner changes on the lockscreen, which allows physically proximate attackers to gain privileges by modifying a setting, aka internal bug 30107438.
https://android.googlesource.com/platform/frameworks/base/+/6ca6cd5a50311d58a1b7bf8fbef3f9aa29eadcd5
http://www.securitytracker.com/id/1036763