How should security teams run user access reviews for high-risk systems and cloud environments?

Why This Matters for Security Teams

user access review are often treated as an administrative exercise, but for high-risk systems and cloud environments they are one of the few moments when stale entitlements, inherited group memberships, and forgotten privileged paths can be removed before they become an incident. The review has to reach beyond named users to include service accounts, delegated access, and third-party relationships, or the most dangerous exposure remains untouched. Current guidance from the NIST Cybersecurity Framework 2.0 and OWASP Non-Human Identity Top 10 both point to continuous governance, not one-time paperwork.

NHIMG’s The State of Non-Human Identity Security reports that only 1.5 out of 10 organisations are highly confident in their ability to secure NHIs, which matters because access reviews usually miss the non-human layer until it has already accumulated privilege. That gap becomes more severe in cloud estates where roles, tokens, and integrations change faster than review cadences can keep up. In practice, many security teams discover excessive access only after an audit, an outage, or a credential leak has already exposed the environment.

How It Works in Practice

Effective reviews start with scope, not spreadsheets. Security teams should rank systems by data sensitivity, privilege depth, and blast radius, then review the smallest set of users that can still meaningfully reduce risk. That means grouping by application owner, business function, contractor status, and third-party access path, rather than sending one generic certification to the whole company. For cloud environments, include IAM roles, federated identities, temporary sessions, privileged groups, and keys or tokens attached to automation.

The review decision should compare actual current need against the access path in use today. A manager can validate whether a person still needs access, but the system owner should confirm whether the entitlement is technically necessary and whether there is a safer alternative such as read-only access, a time-bound elevation, or a workflow approval. Where the access is tied to secrets or machine identities, the review should check whether the credential is still active, whether rotation is overdue, and whether the integration is still in production. NHIMG’s NHI Lifecycle Management Guide is useful here because lifecycle state often explains why an entitlement exists in the first place.

• Start with crown-jewel systems and cloud accounts that can alter data, security controls, or billing.
• Validate access against current role, project need, and exception approval, not historical usage alone.
• Revoke access immediately when ownership, employment status, or vendor relationship has changed.
• Record reviewer, approver, evidence, and remediation so the outcome is auditable and repeatable.

Where this guidance breaks down is in fast-moving DevOps and multi-cloud environments with shared roles, ephemeral sessions, and infrastructure-as-code deployments, because the entitlement state may change between the start and end of the review cycle.

Common Variations and Edge Cases

Tighter access review controls often increase operational overhead, so organisations have to balance assurance against review fatigue and business disruption. That tradeoff is especially visible for cloud platforms, where the same person may hold multiple roles across accounts, subscriptions, and environments, and where temporary access is sometimes the right answer. Best practice is evolving toward risk-based reviews that use stronger frequency for privileged and externally exposed systems, and lighter touch for low-risk entitlements that have clear, monitored patterns.

Edge cases need explicit handling. Shared accounts should be replaced, but if they still exist, the review must focus on accountable ownership and session traceability. For third parties, validate both contract status and technical necessity, because access often outlives the business need. For service accounts and workload credentials, a human access review alone is insufficient; the entitlement should be checked against the workload’s function, rotation state, and logging coverage. The broader failure patterns described in NHIMG’s 52 NHI Breaches Analysis and the vendor-reported visibility gaps in The State of Non-Human Identity Security show why reviews must include non-human paths, not just employee entitlements.

There is no universal standard for review frequency across all cloud and high-risk systems yet, but the current guidance suggests aligning the cadence to privilege level, data sensitivity, and change velocity. The review is only effective when revoked access is actually removed, not merely marked accepted.

Related resources from NHI Mgmt Group

• How should security teams run access reviews for non-human identities?
• How should security teams implement cloud user access reviews across SaaS and multi-cloud environments?
• How should security teams run privileged access reviews without missing high-risk accounts?
• How should security teams manage privileged access in SAP S/4HANA environments that span on premises, cloud, and hybrid deployments?