D-Link DAP-2622 Telnet CLI Use of Hardcoded Credentials Authentication Bypass Vulnerability. This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of D-Link DAP-2622 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the CLI service, which listens on TCP port 23. The server program contains hard-coded credentials. An attacker can leverage this vulnerability to bypass authentication on the system. . Was ZDI-CAN-20050.