They often mistake visible group membership for complete privilege visibility. In Active Directory, the ability to perform specific high-impact tasks is what matters, so a review that ignores delegated rights, ownership, and ACL inheritance will miss accounts that can still take over the domain.
Why This Matters for Security Teams
Privileged access reviews in Active Directory are often treated like a checkbox exercise, but the real risk is operational: a review can look complete while still missing accounts that can reset passwords, modify ACLs, take ownership, or inherit rights through nested delegation. That gap matters because AD privilege is rarely captured by direct group membership alone. NHI Management Group’s Ultimate Guide to NHIs notes that only 5.7% of organisations have full visibility into their service accounts, which is a useful warning sign for identity review programs more broadly.
Security teams also overestimate what the directory UI makes easy to see. Effective review requires understanding effective permissions, inheritance, and delegated administration, not just who appears in Domain Admins or a similar high-profile group. The OWASP Non-Human Identity Top 10 reinforces the same pattern: exposed identity paths and weak governance become privilege escalation routes when access is assumed to be static. In practice, many security teams encounter domain takeover conditions only after an incident review, rather than through intentional privilege validation.
How It Works in Practice
A useful AD privileged access review starts by separating visibility from effective authority. The first is what a reviewer can see at a glance. The second is what an account can actually do after group nesting, ACL inheritance, delegated OU rights, AdminSDHolder protection, GPO-linked permissions, and ownership changes are applied. That distinction is where most review failures begin.
Operationally, teams should map accounts to the high-impact actions they can perform, such as resetting privileged passwords, modifying group membership, writing to sensitive directory objects, altering replication-related permissions, or taking ownership of objects and thereby bypassing intended controls. Current guidance suggests reviews should also include service accounts, break-glass accounts, and delegated admin accounts, because these often evade the “who is in what group” model.
- Review nested group membership and transitive access, not only direct assignment.
- Validate effective permissions on sensitive OUs, GPOs, and admin-tier objects.
- Check ACLs for write, modify, take ownership, and reset-password rights.
- Confirm inheritance exceptions and delegated control paths are documented.
- Reconcile stale accounts and orphaned owners, especially after reorgs.
For teams building a stronger review process, the NHI Management Group NHI Lifecycle Management Guide is a useful companion because it frames privilege as something that must be continually validated, not merely approved once. The practical baseline is to combine directory review with policy-as-code checks, high-value object inventory, and periodic effective-access testing, using controls aligned to the NIST Cybersecurity Framework and least-privilege principles.
These controls tend to break down in heavily delegated, legacy AD environments where inherited ACLs, shadow admin paths, and undocumented admin tooling create privilege that is technically valid but impossible to review from the console alone.
Common Variations and Edge Cases
Tighter access review often increases administrative overhead, requiring organisations to balance review depth against directory complexity and change volume. That tradeoff is real, especially in multi-domain forests, merger environments, and enterprises that use third-party administration tools or custom delegation models.
There is no universal standard for this yet, but current guidance suggests several edge cases need explicit handling. Hidden privilege can come from object ownership, not just ACLs; from delegated rights on an OU, not just membership in a privileged group; and from inherited permissions that become effective only under specific child-object conditions. Reviews also need to consider whether a dormant account still has rights to trigger automation, modify scripts, or reach privileged jump hosts.
Where AD is integrated with broader identity governance, the best result usually comes from combining manual attestation with technical effective-access analysis. The NHI Management Group Ultimate Guide to NHIs — Key Challenges and Risks is relevant here because it highlights the visibility and excessive-privilege problems that also surface in AD. For control design, the CISA Zero Trust Maturity Model remains a practical reference point: verify access continuously, reduce standing privilege, and treat effective permissions as the review target, not group labels alone.
Edge cases become most dangerous when organisations assume that a clean privileged-group attestation means the domain is safe, because the highest-risk path is often hiding in delegation, ownership, or inherited ACLs outside the obvious review scope.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 address the attack and risk surface, while NIST CSF 2.0 and NIST Zero Trust (SP 800-207) set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST CSF 2.0 | PR.AC-4 | Privileges must be managed by effective access, not just visible membership. |
| OWASP Non-Human Identity Top 10 | NHI-03 | AD reviews often miss over-privileged identities and hidden access paths. |
| NIST Zero Trust (SP 800-207) | Zero trust requires verifying effective authority at request time, not assuming trust. |
Review and restrict effective AD access paths, including delegation and inheritance, under least-privilege controls.
Related resources from NHI Mgmt Group
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Reviewed and updated by the NHIMG editorial team on July 8, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
