The Advan i6A Android device with a build fingerprint of ADVAN/i6A/i6A:8.1.0/O11019/1523602705:userdebug/test-keys contains a pre-installed app with a package name of com.mediatek.wfo.impl app (versionCode=27, versionName=8.1.0) that allows any app co-located on the device to modify a system property through an exported interface without proper authorization.