A vulnerability, which was classified as critical, was found in Tenda i22 1.0.0.3(4687). Affected is the function formApPortalPhoneAuth of the file /goform/apPortalPhoneAuth. The manipulation of the argument data leads to buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.