This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in Wp-useronline
The WP-UserOnline plugin for WordPress has multiple Stored Cross-Site Scripting vulnerabilities in versions up to, and including 2.88.0. This is due to the fact that all fields in the "Naming Conventions" section do not properly sanitize user input, nor escape it on output. This makes it possible for authenticated attackers, with administrative privileges, to inject JavaScript code into the setting that will execute whenever a user accesses the injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled. (2022-09-06, CVE-2022-2941)
The WP-UserOnline plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘templates[browsingpage][text]' parameter in versions up to, and including, 2.87.6 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers with administrative capabilities and above to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The only affects multi-site installations and installations where unfiltered_html is disabled. (2022-09-06, CVE-2022-2473)
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>