The Schema App Structured Data plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via 'Remove Microdata' Output Filter in all versions up to, and including, 2.3.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires that an administrator has enabled the plugin's 'Remove Microdata' option and approves the malicious comment.