An attacker can access to "Forgot my password" button, as soon as he puts users is valid in the system, the system would issue a message that a password reset email had been sent to user. This way you can verify which users are in the system and which are not.
Metrics
CVSS Version: 3.1 |
Base Score: 5.5 MEDIUM Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L