The built-in local guest account is another well-known name to attackers. It is recommended to rename this account to something that does not indicate its purpose. Even if you disable this account, which is recommended, ensure that you rename it for added security. On Domain Controllers, since they do not have their own local accounts, this rule refers to the built-in Guest account that was established when the domain was first created. Rationale: The Guest account exists on all computers that run the Windows 2000 or newer operating systems. If you rename this account, it is slightly more difficult for unauthorized persons to guess this privileged user name and password combination. Impact: There should be little impact, because the Guest account is disabled by default.
Solution
To establish the recommended configuration via GP, configure the following UI path: Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\Security Options\Accounts: Rename guest account Default Value: Guest. Additional Information: Microsoft Windows Server 2019 Security Technical Implementation Guide: Version 2, Release 1, Benchmark Date: November 13, 2020 Vul ID: V-205910 Rule ID: SV-205910r569188_rule STIG ID: WN19-SO-000040 Severity: CAT II