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 is a good way to create a very insecure Moodle site, and is not recommended, except for testing purposes.
See also
- Using Moodle Security and Privacy forum