report/security/report security check noauth
From MoodleDocs
With the No authentication method enabled, a user can create an account without any kind of authentication from other systems, and with no email-based confirmation that the email address that they have provided is valid, or even exists!
This will create a very insecure Moodle site, and is not recommended for any production site unless the site is protected via some other means.
See also
- Using Moodle Security and Privacy forum