Zte F680 Exploit ❲2026 Edition❳

Because the router fails to check if the user has an active login session, the CGI script executes the command, enabling the Telnet daemon with hardcoded or default credentials. The Flaw: The diagnostic "Ping" tool on the router’s administration panel ( Advanced -> Diagnostics -> Ping ) takes a user-supplied IP address or hostname. Input sanitization is absent. Characters like ; , | , & , or $() are passed directly to the underlying Linux system() call.

POST /cgi-bin/telnet.cgi HTTP/1.1 Host: 192.168.1.1 Cookie: language=english; enabled=1 Content-Length: 50 enable telnet=1&username=admin&password=admin zte f680 exploit

Security researcher Pierre Kim documented in 2021 that the ZTE F680’s firmware contains hardcoded RSA private keys for SSH, allowing anyone with the key to decrypt LAN traffic or impersonate the device. Let’s walk through a realistic exploit chain used by botnets (like Mirai variants) and red-teamers against the ZTE F680. Phase 1: Discovery & Fingerprinting The attacker scans for devices responding on port 80 or 443 with a specific HTTP title: ZTE F680 GPON ONT . The default login page often leaks the firmware version in the HTML source code. Phase 2: Authentication Bypass Using a simple Python script, the attacker sends a POST request to /cgi-bin/telnet.cgi with no session cookie. If the device is vulnerable, the response 200 OK appears, and Telnet is enabled on port 23. Because the router fails to check if the

Introduction: The Router on the Edge The ZTE F680 is a popular Fiber Optical Network Terminal (ONT) / Gateway unit, widely deployed by Internet Service Providers (ISPs) across Europe, Asia, the Middle East, and South America. It is often the "first line of defense" for home and small business networks, managing GPON (Gigabit Passive Optical Network) connectivity, VoIP, Wi-Fi, and routing. Characters like ; , | , & ,