If a user provides bad credentials several times in quick succession, Vault will stop trying to validate their credentials for a while, instead returning immediately with a permission denied error. We call this behavior "user lockout". The time for which a user will be locked out is called “lockout duration”. The user will be able to login after the lockout duration has passed. The number of failed login attempts after which the user is locked out is called “lockout threshold”. The lockout threshold counter is reset to zero after a few minutes without login attempts, or upon a successful login attempt. The duration after which the counter will be reset to zero after no login attempts is called "lockout counter reset". This can defeat both automated and targeted requests i.e, user-based password guessing attacks as well as automated attacks.
The user lockout feature is enabled by default. The default values for "lockout threshold" is 5 attempts, "lockout duration" is 15 minutes, "lockout counter reset" is 15 minutes.
The user lockout feature can disabled as follows:
- It can be disabled globally using environment variable VAULT_DISABLE_USER_LOCKOUT.
- It can be disabled for all supported auth methods (ldap, userpass and approle) or a specific supported auth method using "disable_lockout" parameter within user_lockout stanza in configuration file. Please see user lockout configuration for more details.
- It can be disabled for a specific auth mount using "auth tune". Please see auth tune command or auth tune api for more details.
NOTE: This feature is available from Vault version 1.13 and is only supported by userpass, ldap and approle auth methods.
The precedence for user lockout configuration is as follows:
Configuration for an auth mount using tune >> Configuration for an auth method in config file >> Configuration for "all" auth methods in config file >> Default values.
The precedence for user lockout disable is as follows:
Disable using environment variable VAULT_DISABLE_USER_LOCKOUT >> Configuration for an auth mount using tune >> Configuration for an auth method in config file >> Configuration for "all" auth methods in config file >> Default values.
User lockout parameters can be configured using config file for "all" auth methods or a specific auth method (userpass, ldap, or approle). Please see user lockout configuration for more details.
Please see sys/locked-users API for more details.