A: Do not update. ISP firmware updates automatically re-lock the Top account and may patch the Telnet exploit. Block TR-069 first.
Once inside Telnet, type the following to unlock the web "Top" profile permanently: unlock zte f670l top
When you log into the standard admin interface (usually 192.168.1.1 ), you are using a "User" profile. You see basic Wi-Fi settings and maybe a reboot button. But the "" level—also known as the root or manufacturing administrator profile—remains locked. A: Do not update