# dns_server_sim.py - Simulated DNS server allowing AXFR
from dnslib import DNSRecord, QTYPE, RR, TXT, A
import socketserver, socket

class DNSHandler(socketserver.BaseRequestHandler):
    def handle(self):
        data, sock = self.request
        request = DNSRecord.parse(data)
        reply = request.reply()
        qname = request.q.qname
        if request.q.qtype == QTYPE.AXFR:
            # Vulnerability: allows zone transfer from any client
            reply.add_answer(RR(qname, QTYPE.TXT, rdata=TXT("secret=admin:password123")))
            reply.add_answer(RR(qname, QTYPE.A, rdata=A("192.168.1.1")))
        sock.sendto(reply.pack(), self.client_address)

server = socketserver.ThreadingUDPServer(('0.0.0.0', 53), DNSHandler)
print("DNS server on :53")
server.serve_forever()