This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in Gistpress
XSS exists in the shortcode functionality of the GistPress plugin before 3.0.2 for WordPress via the includes/class-gistpress.php id parameter. This allows an attacker with the WordPress Contributor role to execute arbitrary JavaScript code with the privileges of other users (e.g., ones who have the publish_posts capability). (2020-01-30, CVE-2020-8498)
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>