AD-CFG-20: CRL distribution points count should be retrievable


ID	`AD-CFG-20`
Severity	Info
Suite	Active Directory (on-premises)
Product	Active Directory
Feature	Certificate Services
Security area	Infrastructure hardening
Resource type	CertificateAuthority
Reads from	On-premises Active Directory

What this checks and how to fix it

Certificate Revocation Lists (CRLs) are published at specific locations called CRL distribution points. These endpoints enable relying parties (including AD-integrated components) to check whether certificates have been revoked.

If CRL distribution points are missing, misconfigured, or reduced unexpectedly, revocation checking can fail. That can allow previously revoked certificates to remain effectively trusted longer than intended.

Monitoring the count of CRL distribution points helps detect:

Missing distribution points after CA configuration changes
Unexpected additions (potentially pointing to untrusted or incorrect publishing locations)

Control Type

Operational

Security Recommendation

Ensure CRL distribution points are configured to reliable, access-controlled endpoints.
Validate that all intended distribution points are present and reachable from relying-party networks.
Alert on changes to the number of distribution points—treat deviations as configuration drift.

How the Test Works

The test inspects AD configuration for CRL distribution point entries, counts them, and reports the current number. This provides a lightweight indicator that your revocation publication settings align with expected CA configuration.

Mito check. Author: soulemike. Open-source licences.

Open-source licences. CIS Benchmark material © Center for Internet Security, Inc.; CISA SCuBA baselines are public domain (CC0).