avalex – Automatisch sichere Rechtstexte <= 3.0.3 - Authenticated (Admin+) Stored Cross-Site Scripting

The avalex – Automatisch sichere Rechtstexte plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'avalex_api_key' parameter in versions up to, and including, 3.0.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.