InformationThis policy setting determines the number of failed logon attempts before the account is locked. Setting this policy to 0 does not conform to the benchmark as doing so disables the account lockout threshold.
The STIG recommended state for this setting is: 3 or fewer invalid logon attempt(s), but not 0.
Note: Password Policy settings (section 1.1) and Account Lockout Policy settings (section 1.2) must be applied via the Default Domain Policy GPO in order to be globally in effect on domain user accounts as their default behavior. If these settings are configured in another GPO, they will only affect local user accounts on the computers that receive the GPO. However, custom exceptions to the default password policy and account lockout policy rules for specific domain users and/or groups can be defined using Password Settings Objects (PSOs), which are completely separate from Group Policy and most easily configured using Active Directory Administrative Center.
Note #2 The CIS recommended state for this setting is: 10 or fewer invalid logon attempt(s), but not 0, which differs from the STIG recommended state.
Setting an account lockout threshold reduces the likelihood that an online password brute force attack will be successful. Setting the account lockout threshold too low introduces risk of increased accidental lockouts and/or a malicious actor intentionally locking out accounts.
If this policy setting is enabled, a locked-out account will not be usable until it is reset by an administrator or until the account lockout duration expires. This setting may generate additional help desk calls.
If you enforce this setting an attacker could cause a denial of service condition by deliberately generating failed logons for multiple user, therefore you should also configure the Account Lockout Duration to a relatively low value.
If you configure the Account Lockout Threshold to 0, there is a possibility that an attacker's attempt to discover passwords with a brute force password attack might go undetected if a robust audit mechanism is not in place.
SolutionTo establish the recommended configuration via GP, set the following UI path to 10 or fewer invalid login attempt(s), but not 0:
Computer Configuration\Policies\Windows Settings\Security Settings\Account Policies\Account Lockout Policy\Account lockout threshold
0 failed logon attempts.
Microsoft Windows Server 2019 Security Technical Implementation Guide:
Version 2, Release 1, Benchmark Date: November 13, 2020
Vul ID: V-205629
Rule ID: SV-205629r569188_rule
STIG ID: WN19-AC-000020
Severity: CAT II