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 (bosko@defensecode.com).


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
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accurate analyses of large and complex source code projects delivering
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DefenseCode WebScanner is a DAST (Dynamic Application Security
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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

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