Mitel 6800 and 6900 Series SIP phone devices through 2022-04-27 have "undocumented functionality." A vulnerability in Mitel 6800 Series and 6900 Series SIP phones excluding 6970, versions 5.1 SP8 (5.1.0.8016) and earlier, and 6.0 (6.0.0.368) through 6.1 HF4 (6.1.0.165), could allow a unauthenticated attacker with physical access to the phone to gain root access due to insufficient access control for test functionality during system startup. A successful exploit could allow access to sensitive information and code execution.