CVE-2019-15342: Tecno Camon iAir 2 Plus pre‑installed app can run system commands

The Tecno Camon iAir 2 Plus Android device with a build fingerprint of TECNO/H622/TECNO-ID3k:8.1.0/O11019/E-180914V83:user/release-keys contains a pre-installed platform app with a package name of com.lovelyfont.defcontainer (versionCode=7, versionName=7.0.11). This app contains an exported service named com.lovelyfont.manager.FontCoverService that allows any app co-located on the device to supply arbitrary commands via shell script to be executed as the system user that are triggered by writing an attacker-selected message to the logcat log. This app cannot be disabled by the user and the attack can be performed by a zero-permission app. Executing commands as the system user can allow a third-party app to video record the user's screen, factory reset the device, obtain the user's notifications, read the logcat logs, inject events in the Graphical User Interface (GUI), and obtains the user's text messages, and more. Executing commands as the system user can allow a third-party app to factory reset the device, obtain the user's notifications, read the logcat logs, inject events in the GUI, change the default Input Method Editor (IME) (e.g., keyboard) with one contained within the attacking app that contains keylogging functionality, and obtains the user's text messages, and more.