Dhis 2 Cross-site Scripting

DHIS 2 is an open source information system for data capture, management, validation, analytics and visualization. Through various features of DHIS2, an authenticated user may be able to upload a file which includes embedded javascript. The user could then potentially trick another authenticated user to open the malicious file in a browser which would trigger the javascript code, resulting in a cross-site scripting (XSS) attack. DHIS2 administrators should upgrade to the following hotfix releases: 2.36.12.1, 2.37.8.1, 2.38.2.1, 2.39.0.1. Users unable to upgrade may add the following simple CSP rule in your web proxy to the vulnerable endpoints: `script-src 'none'`. This workaround will prevent all javascript from running on those endpoints. (2022-12-08, CVE-2022-41947)

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>