Multiple Vulnerabilities in D-Link DIR-600 and DIR-300

tldr; If you have a D-Link router you should try if this command produces any output.

  curl --data "cmd=ls" http://<Router-IP>:8080/command.php

(also try Port 80 instead of 8080, the port number can vary)

If it does then your router has a serious vulnerability (exploitable from the internet on some models) and you should look into patching ASAP.