Featured Image WordPress Plugin Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the Featured Image plugin for WordPress, affecting all versions through 2.1. This vulnerability arises from inadequate input sanitization and output escaping, allowing authenticated attackers with administrator-level permissions to inject arbitrary scripts into image metadata. The injected scripts are executed when users access the affected pages. This issue 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.

Reproduction

To reproduce this vulnerability, an administrator must upload an image and include malicious payloads in the alt text and caption. After uploading, the image can be set as the featured image for a post. When the post is viewed, the cross-site scripting payloads will be executed.

Remediation

Users are advised to update to Featured Image version 2.2, where this vulnerability has been fixed.