usd-2019-0069 | Zen Cart / v1.5.6d

Advisory ID: usd-2019-0069
CVE Number: CVE-2020-6578
Affected Product: Zen Cart
Affected Version: v1.5.6d
Vulnerability Type: XSS
Security Risk: Medium
Vendor: Zen Cart
Vendor URL:
Vendor Status: fixed


A reflected XSS attack (or non-persistent attack) occurs when a malicious script is reflected off of a web application to the victim’s browser. The attack is typically delivered via email or a web site and activated through a link, which sends a request to a website with a vulnerability that enables execution of malicious scripts. The main_page parameter is vulnerable to reflected XSS in the /includes/templates/template_default/common/tpl_main_page.php and the /includes/templates/responsive_classic/common/tpl_main_page.php files.

Proof of Concept (PoC)

It is possible to send one of the two following requests to inject HTML code into the application:

The following HTTP response shows the injected JavaScript payload that would cause an alert box to pop up.

The vulnerable code was located inside includes/templates/responsive_classic/common/tpl_main_page.php


All user supplied input should be encoded on delivery or before rendering to prevent the injection of HTML code.


  • 2019-12-16 Vulnerability discovered by Gerbert Roitburd and Markus Schader
  • 2020-01-08 Initial contact with vendor
  • 2020-01-22 Vulnerability fixed by vendor
  • 2021-02-26 Security advisory released


This security vulnerability was discovered by Gerbert Roitburd and Markus Schader of usd AG.


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to usd AG

In accordance with usd AG’s Responsible Disclosure Policy, all vendors have been notified of the existence of these vulnerabilities.


The information provided in this security advisory is provided „as is“ and without warranty of any kind. Details of this security advisory may be updated in order to provide as accurate information as possible.