Tenda AC21 Buffer Overflow Vulnerability

Tenda AC21 is a wireless router from Tenda (China). Tenda AC21 V16.03.08.15 is vulnerable to a buffer overflow vulnerability, which originates in the form_fast_setting_wifi_set function of /bin/httpd for lack of length checking of input data, and can be exploited by an attacker to cause httpd to restart via the payload.