Zte F680 Exploit Info

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.

Last updated: October 2024. This article is for educational purposes only. The author and platform are not responsible for misuse of this information. zte f680 exploit

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. Security researcher Pierre Kim documented in 2021 that

This results in Remote Code Execution (RCE) with root privileges, as the web server runs with high system privileges. While not a "software bug" per se, many ISPs never change the manufacturer default passwords. However, the ZTE F680 has a known hidden backdoor: the user account with password Zte521 (or variations like root / Zte521@hn ). These accounts bypass the standard login lockout policies, making brute-forcing trivial. The default login page often leaks the firmware

An attacker on the same Local Area Network (LAN) – or worse, a malicious JavaScript on a website the user visits (CSRF) – could send a crafted HTTP request like this: