D-Link DIR-2150 HNAP Incorrect Implementation of Authentication Algorithm Authentication Bypass Vulnerability. This vulnerability allows network-adjacent attackers to bypass authentication on affected installations of D-Link DIR-2150 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the SOAP API interface, which listens on TCP port 80 by default. A crafted authentication header can cause authentication to succeed without providing proper credentials. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-20910.