RCE Security Advisory
https://www.rcesecurity.com


1. ADVISORY INFORMATION
=======================
Product:        SlickQuiz
Vendor URL:     https://wordpress.org/plugins/slickquiz/
Type:           SQL Injection [CWE-74]
Date found:     2019-05-30
Date published: 2019-09-10
CVSSv3 Score:   8.1 (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N)
CVE:            CVE-2019-12516


2. CREDITS
==========
This vulnerability was discovered and researched by Julien Ahrens from
RCE Security.


3. VERSIONS AFFECTED
====================
SlickQuiz for Wordpress 1.3.7.1 (latest)


4. INTRODUCTION
===============
SlickQuiz is a plugin for displaying and managing pretty, dynamic quizzes. It
uses the SlickQuiz jQuery plugin.

(from the vendor's homepage)


5. VULNERABILITY DETAILS
========================
The SlickQuiz Wordpress plugin is vulnerable to multiple authenticated SQL
Injections whenever the "id" parameter is involved. It is not even required to
have any quiz created, just the pure presence of the plugin makes the
installation vulnerable.

Since all access levels from Subscriber (the lowest possible rights) to Admin
basically have access to the plugin, it is possible to escalate privileges quite easily.

To name just a few vulnerable endpoints:

/wp-admin/admin.php?page=slickquiz-scores&id=(select*from(select(sleep(5)))a)
/wp-admin/admin.php?page=slickquiz-edit&id=(select*from(select(sleep(5)))a)
/wp-admin/admin.php?page=slickquiz-preview&id=(select*from(select(sleep(5)))a)


6. RISK
=======
The vulnerability can be used by an authenticated attacker (lowest possible
rights of Subscriber are sufficient) to read sensitive contents from the backend
database and therefore compromise all kinds of information, which is stored in
the database. This could be sensitive authentication information like passwords
or customer and employee information like email addresses and could also be used
to escalate privileges to Admin which in return leads to RCE on the Wordpress
installation via the plugin functionality.


7. SOLUTION
===========
None (Remove the plugin)


8. REPORT TIMELINE
==================
2019-05-30: Discovery of the vulnerability during H1-4420
2019-06-01: CVE requested from MITRE
2019-06-02: MITRE assigns CVE-2019-12516
2019-06-10: Contacted vendor using their publicly listed email address
2019-06-19: Contacted vendor using their publicly listed email address
2019-06-22: Contacted vendor using their publicly listed email address
2019-08-28: No response from vendor
2019-09-10: Public disclosure.


9. REFERENCES
=============
https://www.rcesecurity.com/2019/09/H1-4420-From-Quiz-to-Admin-Chaining-Two-0-Days-to-Compromise-an-Uber-Wordpress/