The Theme My Login plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 7.1.7. This is due to missing or incorrect nonce validation on the tml_admin_save_ms_settings() function. This makes it possible for unauthenticated attackers to update the theme's settings via a forged request granted they can trick a site administrator into performing an action such as clicking on a link. Please note that this only affects multi-site instances.
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.