Input validation

The Xiaomi Cepheus Android device with a build fingerprint of Xiaomi/cepheus/cepheus:9/PKQ1.181121.001/V10.2.6.0.PFAMIXM:user/release-keys contains a pre-installed app with a package name of com.qualcomm.qti.callenhancement app (versionCode=28, versionName=9) that allows unauthorized microphone audio recording via a confused deputy attack. This capability can be accessed by any app co-located on the device. This app allows a third-party app to use its open interface to record telephone calls to external storage.