This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DAP-1860 1.04B03_HOTFIX WiFi extenders. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the HNAP service, which listens on TCP port 80 by default. When parsing the SOAPAction header, the process does not properly validate a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of the device. Was ZDI-CAN-10084.