This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in App Studio
An issue was discovered in UiPath App Studio 21.4.4. There is a persistent XSS vulnerability in the file-upload functionality for uploading icons when attempting to create new Apps. An attacker with minimal privileges in the application can build their own App and upload a malicious file containing an XSS payload, by uploading an arbitrary file and modifying the MIME type in a subsequent HTTP request. This then allows the file to be stored and retrieved from the server by other users in the same organization. (2021-12-14, CVE-2021-44043)
Why Cross-site Scripting can be dangerous
Cross site scripting is an attack where a web page executes code that is injected by an adversary. It usually appears, when users input is presented. This attack can be used to impersonate a user, take over control of the session, or even steal API keys.
The attack can be executed e.g. when you application injects the request parameter directly into the HTML code of the page returned to the user:
https://server.com/confirmation?message=Transaction+Complete
what results in:
<span>Confirmation: Transaction Complete</span>
In that case the message can be modified to become a valid Javascript code, e.g.:
https://server.com/confirmation?message=<script>dangerous javascript code here</script>
and it will be executed locally by the user's browser with full access to the user's personal application/browser data:
<span>Confirmation: <script>dangerous javascript code here</script></span>