AMP Enhancer Stored Cross-Site Scripting Vulnerability in WordPress

A stored cross-site scripting vulnerability has been identified in the AMP Enhancer plugin for WordPress, specifically in versions through 1.0.49. This issue arises from inadequate input sanitization and output escaping in the AMP Custom CSS setting. As a result, authenticated attackers with Administrator-level access can inject arbitrary scripts into pages, which will execute when users access the affected pages. This vulnerability is present in multi-site installations where unfiltered_html has been disabled.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, where injected scripts are executed in the context of the user viewing the page.