Hacking D-Link Routers With HNAP – Multiple D-Link routers suffer from insecure implementations of the Home Network Administration Protocol which allow unauthenticated and/or unprivileged users to view and configure administrative settings on the router. Further, the mere existence of HNAP allows attackers to completely bypass the CAPTCHA login features that D-Link has made available in recent firmware releases.
You can download it from the following link: https://packetstormsecurity.com/files/download/84989/dlink_hnap_captcha.pdf
Source: https://packetstormsecurity.com/files/84989/Hacking-D-Link-Routers-With-HNAP.html