Improper Restriction of Excessive Authentication Attempts

Summary

A flaw was found in Moodle. A remote attacker could exploit a lack of proper rate limiting in the confirmation email service. This vulnerability allows attackers to more easily enumerate or guess user credentials, facilitating Brute Force attacks against user accounts. The issue affects versions prior to 4.1.22, 4.2.x through 4.4.x prior to 4.4.12, 4.5.x prior to 4.5.8, 5.0.x prior to 5.0.4, and 5.1.x prior to 5.1.1.