Magento Downloadable Products Cross Site Scripting

`DefenseCode Security Advisory  
Magento Stored Cross-Site Scripting a Downloadable Products  
  
  
Advisory ID: DC-2018-03-003  
Advisory Title: Magento Stored Cross-Site Scripting a Downloadable Products  
Advisory URL: http://www.defensecode.com/advisories.php  
Software: Magento  
Version: Magento 2.0 prior to 2.0.18, Magento 2.1 prior to  
2.1.12, Magento 2.2 prior to 2.2.3  
Vendor Status: Vendor contacted, vulnerability fixed  
Release Date: 06/03/2018  
Risk: MEDIUM  
  
  
  
1. General Overview  
===================  
During the security audit of Magento Open Source 2 a stored cross-site  
scripting vulnerability was discovered that could lead to administrator  
account takeover by a lower privileged administrator, putting the  
website customers and their payment information at risk.  
  
  
2. Software Overview  
====================  
Magento is an ecommerce platform built on open source technology  
which provides online merchants with a flexible shopping cart system,  
as well as control over the look, content and functionality of their  
online store. Magento offers powerful marketing, search engine  
optimization, and catalog-management tools. It is a leading  
enterprise-class eCommerce platform, empowering over 200,000  
online retailers.  
  
Homepage:  
http://www.magento.com  
  
  
3. Vulnerability Description  
============================  
During the security analysis of Magento Open Source 2 it was  
discovered that a lower privileged admin with access to Products  
editing can upload a file for a downloadable product using a random  
extension (ex. .aaa). Extensions like .html or .php are disallowed  
but if the content of the file is HTML the application will serve  
the file as such as there is no content disposition header set to  
force the download. The attacker can then use the link by enticing  
the higher privileged admin to open it.  
  
Unlike a typical XSS which is often limited by length and payload  
type, this gives an attacker a whole HTML file to work with.  
  
  
4. Solution  
===========  
Vendor fixed the reported security issues and released a new version.  
All users are strongly advised to update to the latest available  
version.  
  
  
5. Credits  
==========  
Discovered by Bosko Stankovic ([email protected]).  
  
  
6. Disclosure Timeline  
======================  
10/11/2017 Vendor contacted through Bugcrowd platform  
15/11/2017 Vendor responded  
28/02/2018 Vulnerability fixed  
06/03/2018 Advisory released  
  
  
7. About DefenseCode  
====================  
DefenseCode L.L.C. delivers products and services designed to analyze  
and test web, desktop and mobile applications for security  
vulnerabilities.  
  
DefenseCode ThunderScan is a SAST (Static Application Security  
Testing, WhiteBox Testing) solution for performing extensive security  
audits of application source code. ThunderScan SAST performs fast and  
accurate analyses of large and complex source code projects delivering  
precise results and low false positive rate.  
  
DefenseCode WebScanner is a DAST (Dynamic Application Security  
Testing, BlackBox Testing) solution for comprehensive security audits  
of active web applications. WebScanner will test a website's security  
by carrying out a large number of attacks using the most advanced  
techniques, just as a real attacker would.  
  
Subscribe for free software trial on our website  
http://www.defensecode.com/ .  
  
E-mail: defensecode[at]defensecode.com  
  
Website: http://www.defensecode.com  
Twitter: https://twitter.com/DefenseCode/  
`