The Download Manager plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'redirect_to' parameter in all versions up to, and including, 3.3.46. This is due to insufficient input sanitization and output escaping on the 'redirect_to' GET parameter in the login form shortcode. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
https://www.wpdownloadmanager.com/doc/short-codes/wpdm_login_form-user-login-form-short-code/
https://plugins.trac.wordpress.org/browser/download-manager/tags/3.3.46/src/User/Login.php#L137