usd-2020-0029 | NeoPost Mail Accounting Software Pro 5.0.6

Advisory ID: usd-2020-0029
CVE Number: CVE-2020-27974
Affected Product: NeoPost Mail Accounting Software Pro
Affected Version: 5.0.6
Vulnerability Type: Reflected XSS
Security Risk: High
Vendor URL:
Vendor Status: Not fixed


Reflected XSS attack (or non-persistent attack) occurs when a malicious script is reflected off of a web application to the victims 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.

Proof of Concept (PoC)

The XSS attack was possible via the following url: http://localhost/php/Commun/FUS_SCM_BlockStart.php?code=%3Cscript%3Ealert(%27XSS%27)%3C/script%3E


Make sure to encode and/or filter the user supplied input.


  • 2020-03-25 This vulnerability was found during a Penetration Test on one of our customers
  • 2020-03-26 First attempt to contact vendor
  • 2020-05-14 Second attempt to contact vendor
  • 2020-08-06 Third attempt to contact vendor
  • 2020-09-23 Vendor was informed of upcoming release
  • 2020-10-27 Security Advisory released


This security vulnerability was found by Tim Kranz and Lars Neumann of usd AG.


In order to protect businesses against hackers and criminals, we always have to keep our skills and knowledge up to date. Thus, security research is just as important for our work as is building up a security community to promote the exchange of knowledge. After all, more security can only be achieved if many individuals take on the task.

Our CST Academy and our usd HeroLab are essential parts of our security mission. We share the knowledge we gain in our practical work and our research through training courses and publications. In this context, the usd HeroLab publishes a series of papers on new vulnerabilities and current security issues.

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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.