Vulnerability Discussion

The built-in guest account is a well-known user account on all Windows systems and, as initially installed, does not require a password. This can allow access to system resources by unauthorized users. Renaming this account to an unidentified name improves the protection of this account and the system.

Check

Verify the effective setting in Local Group Policy Editor.

Run "gpedit.msc".

Navigate to Local Computer Policy >> Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options.

If the value for "Accounts: Rename guest account" is not set to a value other than "Guest", this is a finding.

For server core installations, run the following command:

Secedit /Export /Areas SecurityPolicy /CFG C:\Path\FileName.Txt

If "NewGuestName" is not something other than "Guest" in the file, this is a finding.

Fix

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Accounts: Rename guest account" to a name other than "Guest".