I believe you are looking for reported security vulnerabilities for this model:
http://forum.tp-link.com/showthread.php?78603-Misfortune-Cookie-vulnerability-reported-for-TP-Link-wireless-routers (TP Forum is a good place to start) http://www.ncf.ca/ncf/support/wiki/CERT-announced_vulnerability_of_TP-Link_modem/router General search page here: https://duckduckgo.com/?q=TP-LINK+TD-W8961ND+modem+vulnerabilities
Hope this helps.