Windows Server 2025 must be configured for name-based strong mappings for certificates.

STIG ID: WN25-DC-000406  |  SRG: SRG-OS-000080-GPOS-00048 |  Severity: medium (CAT II)  |  CCI: CCI-000213 |  Vulnerability Id: V-278173

Vulnerability Discussion

Weak mappings give rise to security vulnerabilities and demand hardening measures. Certificate names must be correctly mapped to the intended user account in Active Directory. A lack of strong name-based mappings allows certain weak certificate mappings, such as Issuer/Subject AltSecID and User Principal Names (UPN) mappings, to be treated as strong mappings.

Check

This applies to domain controllers. This is not applicable for member servers.

Verify the effective setting in Local Group Policy Editor.

Run gpedit.msc.

Navigate to Local Computer Policy >> Computer Configuration >> Administrative Template >> System >> KDC >> Allow name-based strong mappings for certificates.

If "Allow name-based strong mappings for certificates" is not "Enabled", this is a finding.

Fix

Configure the policy value for Computer Configuration >> Administrative Template >> System >> KDC >> Allow name-based strong mappings for certificates to "Enabled".

The policy must contain exactly one certificate thumbprint per rule, with each rule represented as a tuple. Thumbprints must be unique and cannot be repeated in multiple rules. The sections of each tuple that are separated by semi-colons must be in the stated order, while the fields separated by commas can be in any order. The rules themselves are separated by new lines.