The AWS AWSCloudTrail_ReadOnlyAccess Managed Policy grants read-only access to AWS CloudTrail configuration and activity information. It lets a principal inspect trails, event history, and related settings without modifying logging. Use it for audit review and investigation, and confirm that no separate permissions allow deletion, alteration, or suppression of trail data.
What this policy lets you inspect in CloudTrail
The key point is that this is a read-only AWS managed policy for CloudTrail. It is meant for viewing trail configuration, event history, and related operational detail, so a reviewer can understand what is being logged without changing the logging setup itself. That makes it suitable for audit, troubleshooting, and security investigation.
Because the policy is read-only, the practical boundary is as important as the allowed access. It supports review of CloudTrail state, but it should not be confused with permissions to create, delete, stop, or rewrite trails, or to alter how logging is delivered and retained. If a principal can make those changes, that power comes from some other permission.
For practitioners who need a broader view of how AWS permissions are evaluated, the AWS IAM Policies and Roles Guide is the best companion resource because CloudTrail access is usually understood in the context of IAM policy evaluation, attached roles, and explicit deny behaviour.
Why read-only CloudTrail access is still sensitive
Read-only access to audit telemetry can still expose security-sensitive information. CloudTrail records can reveal account structure, API activity patterns, role usage, and investigative leads that help an operator understand what happened before or during an incident. That means this policy is not harmless just because it cannot modify logs.
The main security concern is that visibility can assist both defenders and attackers. A legitimate investigator uses it to confirm suspicious activity, while an attacker with the same visibility can learn which services are active, which identities are used, and how far their actions may already have reached. That is why read access should be granted only to principals that genuinely need it.
If you are right-sizing broader cloud privilege around this kind of access, the Cloud PAM and CIEM Guide is useful because it frames effective permissions, privilege reduction, and safe review of granted versus used access.
How to use it safely in review and investigation workflows
This policy is most appropriate for audit teams, security engineers, and responders who need to verify trail coverage, inspect historical events, and confirm whether logging is intact. It is a review tool, not an administrative control, so it should normally sit alongside separate change permissions that are more tightly restricted.
When using it for investigation, the useful question is not only what the principal can see, but whether that principal can also interfere elsewhere. If a user has another permission that can stop logging, delete trails, or alter destination settings, the read-only policy does not protect you from suppression or tampering risk. The review surface must therefore be assessed together with the rest of the principal’s entitlement set.
For environments that need a tighter permission boundary around privileged access, the Privileged Access Management Guide and the Just-in-Time Access and Zero Standing Privilege Guide both help you separate investigative access from standing administrative power.
Risk and Threat Considerations
Read-only access to CloudTrail data can still create exposure if it is granted too broadly, because the same telemetry that supports incident response can also reveal operational patterns, identity usage, and gaps in monitoring. The danger rises when the principal holding this policy also has unrelated permissions that can change or suppress logging.
Failure mechanism: A principal uses legitimate read access to map sensitive activity, then relies on separate permissions, misconfiguration, or privilege overlap to tamper with trails, disable logging, or hide follow-on actions.
Impact: Investigators may lose confidence in the audit record, responders may miss the earliest indicators of compromise, and the organisation may retain a false assumption that logging remained intact throughout the event.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
NIST SP 800-53 Rev 5 and CIS Controls v8 set the technical controls, while ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | AU-6 — Audit Review, Analysis, and Reporting | CloudTrail read access supports audit review and event analysis. |
| AC-6 — Least Privilege | The policy should be limited to readers who need audit visibility only. | |
| AU-9 — Protection of Audit Information | CloudTrail data can be sensitive and should not be alterable by readers. | |
| Recommendation — Use AU-6 to review CloudTrail events and investigate suspicious activity. Apply AC-6 to restrict CloudTrail read access to investigation roles. Use AU-9 to protect CloudTrail logs from unauthorized modification or suppression. | ||
| CIS Controls v8 | CIS-5 — Account Management | CloudTrail access should be governed through tightly assigned identities and roles. |
| Recommendation — Restrict CloudTrail visibility to approved accounts and roles only. | ||
| ISO/IEC 27001:2022 | A.8.15 — Logging | CloudTrail is a core AWS logging mechanism and this policy is for log review. |
| Recommendation — Protect and review CloudTrail logs under A.8.15. | ||
Practitioner Guidance
What to verify: Confirm that the principal using this policy can only read CloudTrail data and does not inherit any separate permission that can stop, delete, or reconfigure trails. If the same identity also administers logging infrastructure, treat the access model as higher risk than the policy name suggests.
Decision rule: If the goal is audit review or forensic investigation, this policy is appropriate; if the goal is operational administration, use a separate privileged path with stronger controls and narrower scope. The access pattern should match the task, not the convenience of reusing one role for both viewing and change.
Practitioner takeaway: Read-only CloudTrail access is safest when it is treated as evidence access, not administrative authority, and when no adjacent permission quietly turns visibility into the ability to suppress the record.