The VideoZen plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 1.0.1. This is due to insufficient input sanitization and output escaping in the videozen_conf() function. The 'lang' POST parameter is stored directly via update_option() without any sanitization, and later echoed inside a <textarea> element without applying esc_textarea() or any equivalent escaping function. This makes it possible for authenticated attackers with Administrator-level access and above to inject arbitrary web scripts into the plugin settings page that will execute whenever any user accesses that page.