Advisory: Cross-Site Scripting in myfactory.FMS  
During a penetration test, a reflected cross-site scripting  
vulnerability (XSS) was found in the myfactory.FMS login form. If a user  
opens an attacker-prepared link to the application, attackers can run  
arbitrary JavaScript code in the user's browser.  
Product: myfactory.FMS  
Affected Versions: <= 7.1-911  
Fixed Versions: 7.1-912 and later  
Vulnerability Type: Cross-Site Scripting  
Security Risk: medium  
Vendor URL:  
Vendor Status: fixed version released  
Advisory URL:  
Advisory Status: published  
"With myfactory, you get a modern accounting application for your business. It  
covers every functionality necessary for an accounting system."  
(translated from German from the vendor's homepage)  
More Details  
The myfactory.FMS web application[0] allows users to login with a username and  
password. If the password is wrong, the application redirects to a URL similar  
to the following:  
The application then opens a dialogue telling the user that their  
username or password are wrong and uses the value of the parameter UID  
to prefill the login form resulting in the following source code:  
<input NAME="txtUID" VALUE="RedTeam"  
onkeypress="OnKeyPress(event)" placeholder="Benutzername" >  
The UID parameter gets reflected without applying any encoding to it.  
A similar problem arises when the login leads to an error. This  
introduces a new parameter named 'Error':  
The value of the Error parameter gets appended without encoding in the  
javascript function mOnLoad resulting in the following code:  
function mOnLoad(  
var sParams;  
alert('Das System konnte Sie nicht anmelden.\n RedTeam_Error');  
Proof of Concept  
The XSS in the UID parameter can be triggered with the following URL:"><script>alert("RedTeam+Pentesting")</script><span+"  
This will lead to the following HTML returned by the server:  
<input NAME="txtUID" VALUE=""><script>alert("RedTeam Pentesting")</script><span ""  
onkeypress="OnKeyPress(event)" placeholder="Benutzername" >  
To demonstrate the XSS via the Error parameter, the following URL can be  
This will lead to the following JavaScript embedded in the HTML website  
returned by the server:  
function mOnLoad(  
var sParams;  
alert('Das System konnte Sie nicht anmelden.\n ');alert("RedTeam+Pentesting");//');  
Install Version 7.1-912 or later.  
Security Risk  
This security vulnerability allows to execute arbitrary JavaScript code in  
users' browsers if they access URLs prepared by attackers. This provides many  
different possibilities for further attacks against these users. The  
vulnerability could for example be exploited to display a fake login to obtain  
credentials and consequently access a company's accounting information. Since  
attackers might be able to get access to sensitive financial data, but users  
have to actively open an attacker-defined link, this vulnerability is estimated  
to pose a medium risk.  
2021-05-07 Vulnerability identified  
2021-05-27 Customer approved disclosure to vendor  
2021-06-07 Vendor notified, support confirms vulnerability and  
implements fix. Support says vendor does not agree to a  
public advisory.  
2021-06-10 Vendor contacts RedTeam Pentesting, reiterates that  
no advisory should be released. Vendor acknowledges  
public release after 90 days.  
2021-10-04 Customer confirms update to fixed version  
2021-10-13 Advisory released  
RedTeam Pentesting GmbH  
RedTeam Pentesting offers individual penetration tests performed by a  
team of specialised IT-security experts. Hereby, security weaknesses in  
company networks or products are uncovered and can be fixed immediately.  
As there are only few experts in this field, RedTeam Pentesting wants to  
share its knowledge and enhance the public knowledge with research in  
security-related areas. The results are made available as public  
security advisories.  
More information about RedTeam Pentesting can be found at:  
Working at RedTeam Pentesting  
RedTeam Pentesting is looking for penetration testers to join our team  
in Aachen, Germany. If you are interested please visit:  
RedTeam Pentesting GmbH Tel.: +49 241 510081-0  
Dennewartstr. 25-27 Fax : +49 241 510081-99  
52068 Aachen  
Germany Registergericht: Aachen HRB 14004  
Geschäftsführer: Patrick Hof, Jens Liebchen