The Trusted Execution Environment (TEE) module driver of Mate 9 and Mate 9 Pro smart phones with software versions earlier than MHA-AL00BC00B221 and versions earlier than LON-AL00BC00B221 has a use after free (UAF) vulnerability. An attacker tricks a user into installing a malicious application, and the application can start multiple threads and try to create and free specific memory, which could triggers access memory after free it and causes a system crash or arbitrary code execution.