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.

Missing Authorization vulnerability in vberkel Schema App Structured Data schema-app-structured-data-for-schemaorg allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects Schema App Structured Data: from n/a through <= 1.23.1.

The Schema App Structured Data plugin for WordPress is vulnerable to Reflected Cross-Site Scripting due to the use of addqueryarg without appropriate escaping on the URL in all versions up to, and including, 2.2.4. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

The Schema App Structured Data plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.2.0. This is due to missing or incorrect nonce validation on the MarkUpdate function. This makes it possible for unauthenticated attackers to update and delete post metadata via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

The Schema App Structured Data plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the MarkupUpdate function in all versions up to, and including, 2.2.0. This makes it possible for authenticated attackers, with subscriber access or higher, to update or delete post metadata.