Unauthenticated Stack Buffer Overflow in NETGEAR R6700 httpd

This repository provides a working exploit for CVE-2020-15416, a buffer overflow vulnerability in the httpd service of Netgear R7000 WiFi routers. The main exploit script, 'exploit_r7000.py', is a Python script that crafts and sends a malicious HTTP POST request to the '/upgrade_check.cgi' endpoint on the target router. The payload leverages a buffer overflow to execute a command that starts a telnet daemon (utelnetd) on port 6666, granting the attacker a root shell via telnet. The repository also includes a 'nvram-faker' subdirectory, which contains a C library and utilities to emulate NVRAM for embedded Linux environments. This is useful for researchers or exploit developers who wish to emulate the router firmware in QEMU for debugging and testing. The included documentation and scripts (such as 'setupdebuggerenv.txt') provide detailed instructions for setting up a QEMU-based emulation and debugging environment, including the use of LD_PRELOAD to fake NVRAM responses. The exploit is operational and provides a real payload (telnet shell). The codebase includes both the exploit and supporting tools for emulation and debugging, making it suitable for both practical exploitation and research purposes. The main attack vector is network-based, targeting the router's web interface over HTTP.