The UserPro plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 5.1.0. This is due to missing or incorrect nonce validation on the 'userpro_save_userdata' function. This makes it possible for unauthenticated attackers to update the user meta and inject malicious JavaScript via a forged request, granted they can trick a site administrator into performing an action such as clicking on a link.
CWE-352, CWE-352