TP-Link WR740N V6 has a stack overflow vulnerability via the ssid parameter in /userRpm/popupSiteSurveyRpm.htm url.

A password-disclosure issue in the web interface on certain TP-Link devices allows a remote attacker to get full administrative access to the web panel. This affects WA901ND devices before 3.16.9(201211) beta, and Archer C5, Archer C7, MR3420, MR6400, WA701ND, WA801ND, WDR3500, WDR3600, WE843N, WR1043ND, WR1045ND, WR740N, WR741ND, WR749N, WR802N, WR840N, WR841HP, WR841N, WR842N, WR842ND, WR845N, WR940N, WR941HP, WR945N, WR949N, and WRD4300 devices.