On November 3rd, 2019, we have reported a critical vulnerability affecting the Android Bluetooth subsystem. This vulnerability has been assigned CVE-2020-0022 and was now patched in the latest security patch from February 2020. The security impact is as follows:

On Android 8.0 to 9.0, a remote attacker within proximity can silently execute arbitrary code with the privileges of the Bluetooth daemon as long as Bluetooth is enabled. No user interaction is required and only the Bluetooth MAC address of the target devices has to be known. For some devices, the Bluetooth MAC address can be deduced from the WiFi MAC address. This vulnerability can lead to theft of personal data and could potentially be used to spread malware (Short-Distance Worm).

On Android 10, this vulnerability is not exploitable for technical reasons and only results in a crash of the Bluetooth daemon.

Android versions even older than 8.0 might also be affected but we have not evaluated the impact.

Users are strongly advised to install the latest available security patch from February 2020. If you have no patch available yet or your device is not supported anymore, you can try to mitigate the impact by some generic behavior rules:

Only enable Bluetooth if strictly necessary. Keep in mind that most Bluetooth enabled headphones also support wired analog audio.

Keep your device non-discoverable. Most are only discoverable if you enter the Bluetooth scanning menu. Nevertheless, some older phones might be discoverable permanently.

As soon as we are confident that patches have reached the end users, we will publish a technical report on this vulnerability including a description of the exploit as well as Proof of Concept code.