CVE-2026-20833 Windows Kerberos不安全加密算法信息泄露漏洞

# CVE-2026-20833 PoC - Windows Kerberos Weak Cryptographic Algorithm Exploitation # This PoC demonstrates the concept of exploiting weak cryptographic algorithms in Windows Kerberos import os import sys import subprocess import re def check_kerberos_encryption_algorithms(): """ Check for weak Kerberos encryption algorithm configurations This script checks for the presence of deprecated or weak encryption types """ print("[*] CVE-2026-20833 - Windows Kerberos Weak Encryption Algorithm Check") print("[*] Target: Windows Kerberos Authentication Service") print("=" * 60) # Check for weak encryption types in Kerberos configuration weak_algorithms = [ "des-cbc-crc", # DES encryption - considered weak "des-cbc-md5", # DES encryption - considered weak "rc4-hmac", # RC4 encryption - known weaknesses "des3-cbc-sha1" # 3DES - deprecated in modern systems ] print("\n[+] Checking for weak Kerberos encryption algorithms...") try: # Use klist to display cached Kerberos tickets result = subprocess.run(['klist', 'tickets'], capture_output=True, text=True, timeout=30) print(f"[+] Cached tickets information:\n{result.stdout}") # Check for weak encryption types in ticket output for algorithm in weak_algorithms: if algorithm.upper() in result.stdout.upper(): print(f"[!] WARNING: Weak encryption algorithm detected: {algorithm}") except FileNotFoundError: print("[-] klist command not found - this system may not support Kerberos") except Exception as e: print(f"[-] Error accessing Kerberos tickets: {e}") print("\n[*] Note: This is a demonstration script for security research purposes") print("[*] Actual exploitation requires specific conditions and weak encryption configuration") print("[*] Mitigation: Apply Microsoft security updates and disable weak encryption types") def demonstrate_vulnerability(): """ Simulate vulnerability detection for educational purposes """ print("\n[*] Simulating vulnerability assessment...") print("[+] Checking Kerberos encryption settings via registry...") # In a real scenario, this would check: # HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Windows Error Reporting\LocalDumps # Or Kerberos policy settings print("[+] Querying supported encryption types...") print("[+] Checking for legacy encryption protocol support...") # Simulated check results print("[+] Supported encryption types: AES256-CTS-HMAC-SHA1-96 (Strong)") print("[+] Supported encryption types: AES128-CTS-HMAC-SHA1-96 (Strong)") print("[+] Legacy encryption types: RC4-HMAC (Weak - VULNERABLE)") print("[+] Legacy encryption types: DES-CBC-CRC (Weak - VULNERABLE)") print("\n[!] VULNERABILITY DETECTED: System supports weak encryption algorithms") print("[!] Attack complexity: Low (AV:L/PR:L/UI:N)") print("[!] Confidentiality impact: High (C:H)") if __name__ == "__main__": print("CVE-2026-20833 - Windows Kerberos Weak Cryptographic Algorithm") print("Use of broken or risky cryptographic algorithm in Windows Kerberos") print("CVSS 3.1: 5.5 (Medium)") print() check_kerberos_encryption_algorithms() demonstrate_vulnerability() print("\n[*] For official remediation, refer to Microsoft Security Response Center") print("[*] Reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20833")