SEC Consult Vulnerability Lab Security Advisory < 20210422-0 >  
title: Stored Cross Site Scripting (Outdated software library)  
product: BMD BMDWeb 2.0  
vulnerable version: BMD versions prior to 24.01.21  
fixed version: 24.01.21 and 24.02.11 or higher  
CVE number: -  
impact: High  
found: 2021-02-11  
by: Stefan Viehböck (Office Vienna)  
SEC Consult Vulnerability Lab  
An integrated part of SEC Consult, an Atos company  
Europe | Asia | North America  
Vendor description:  
"BMD develops high-quality business software and is one of the leading software  
manufacturers in Austria. But also many customers in Germany and Switzerland as  
well as in the international European region rely on the software solutions developed  
by BMD."  
Business recommendation:  
The vendor provides a software update which should be installed immediately.  
SEC Consult highly recommends to perform a thorough security review of the BMD Web  
product conducted by security professionals to identify and resolve potential  
further security issues.  
Vulnerability overview/description:  
1) Stored Cross Site Scripting (Outdated software library)  
BMDWeb 2.0 uses DOMPurify version 1.0.10 (released in Feb 19, 2019) for sanitizing  
untrusted user input. This outdated version suffers from many vulnerabilities that allow  
bypasses of the sanitization logic.  
A few examples:  
An attacker can execute arbitrary JavaScript code in the context of the victim's BMD  
session, thus perform all actions in BMD, exfiltrate information, etc.  
Note for DOMPurify users:  
DOMPurify should be updated regularly. The project provides a mailing list with the  
latest security information.  
Further information:  
Additionally, input validation is another measure against Stored Cross Site Scripting.  
Proof of concept:  
1) Stored Cross Site Scripting (Outdated software library)  
The following XSS vector can be used in all kinds of BMD user input fields, e.g.  
time recording comment, service entry comment, etc.  
<math><mtext><table><mglyph><style><![CDATA[</style><img title="]]></mglyph><img&Tab;src=1&Tab;onerror=alert(0)>">  
This JavaScript code will then automatically get executed when the site which contains  
the payload is visited by the victim.  
Vulnerable / tested versions:  
The vulnerability has been found in BMD 23.45.32 (Build 1004581) which was the  
latest version at the time of discovery.  
Vendor contact timeline:  
2021-02-22: Contacting vendor  
2021-02-22: Conference call to discuss vulnerability.  
2021-03-02: Vendor publishes patch.  
2021-04-22: Coordinated release of security advisory.  
Install BMD 24.01.21 or 24.02.11 or higher versions which are available to all customers  
with support contract.  
Advisory URL:  
SEC Consult Vulnerability Lab  
SEC Consult, an Atos company  
Europe | Asia | North America  
About SEC Consult Vulnerability Lab  
The SEC Consult Vulnerability Lab is an integrated part of SEC Consult, an  
Atos company. It ensures the continued knowledge gain of SEC Consult in the  
field of network and application security to stay ahead of the attacker. The  
SEC Consult Vulnerability Lab supports high-quality penetration testing and  
the evaluation of new offensive and defensive technologies for our customers.  
Hence our customers obtain the most current information about vulnerabilities  
and valid recommendation about the risk profile of new technologies.  
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EOF Stefan Viehböck / @2021