Schema & Structured Data for WP & AMP < 1.54.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via User Custom Schema

Description

The Schema & Structured Data for WP & AMP plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'saswp_custom_schema_field' profile field in all versions up to, and including, 1.54 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.