CVE-2021-23017 PoC Scanner

NGINX DNS Overflow Vulnerability Check - CVE-2021-23017 PoC

This Python script checks if an nginx server is potentially vulnerable to the critical CVE-2021-23017 vulnerability, which affects the integrated DNS resolver in nginx and can cause a buffer overflow.

🔍 What does it do?

• Asks the user for a URL.
• Sends an HTTP request with a malicious (very long) Host header.
• If the server has the nginx resolver configured and is vulnerable, it may crash or log errors.
• No malicious code is executed, it is only a passive detection test.

🚀 How to use it

1. Make sure you have Python 3 installed.
2. Run the script:

python3 CVE-2021-23017.py