The Flattr WordPress plugin through 1.2.2 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)
El complemento Flattr WordPress hasta la versión 1.2.2 no sanitiza ni escapa a algunas de sus configuraciones, lo que podría permitir a usuarios con privilegios elevados, como el administrador, realizar ataques de Cross-Site Scripting Almacenado incluso cuando la capacidad unfiltered_html no está permitida (por ejemplo, en una configuración multisitio).
The Flattr plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in all versions up to, and including, 1.2.2 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.
