Android's December 2019 updates patches a small list of system and Qualcomm flaws across the operating system’s two patch levels .
According with Google, a specific flaws (CVE-2019-2232) may allows an attacker to cause a permanent denial of service by simply sending a specifically crafted message .
It has not been announced how this paralyzing message should be crafted, but some clues can be extracted from the patch source code .
How to fix the problem?
You need to install the Android updates of December 2019, if they are not already installed and if they are available for your device.
These instructions  apply to Android version 9:
- Open your phone's Settings app.
- Near the bottom, tap System Advanced System update.
- You'll see your update status. Follow any steps on the screen.
Updates will be available at different times depending on the manufacturer of the device: on Android bullettin page you can find updates from Google, Huawei, LG, Motorola, Nokia and Samsung .