The Application Passwords plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'reject_url' parameter in all versions up to, and including, 0.1.3. This is due to insufficient input sanitization and output escaping on user supplied URLs, which allows javascript: URI schemes to be embedded in the reject_url parameter. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when a user clicks the "No, I do not approve of this connection" button, granted they can successfully trick the victim into performing an action such as clicking on a link.
