AWS AmazonGuardDutyReadOnlyAccess Managed Policy

What This Managed Policy Does

AWS AmazonGuardDutyReadOnlyAccess Managed Policy is a prebuilt AWS IAM policy for viewing Amazon GuardDuty configuration and findings without granting change permissions. It is intended for read-only monitoring, not administration, so the main security benefit is visibility without accidental or unauthorized control.

That distinction matters because GuardDuty findings often inform incident triage, hunting, and governance workflows. A read-only policy lets analysts inspect detectors, delegated administrators, and alerts while preserving a separation between investigation and enforcement.

Why Read-Only Access Still Needs Careful Scope

This policy is narrow in intent, but read-only access can still reveal useful security intelligence about detectors, accounts, regions, and active findings. If a principal also has broader AWS permissions elsewhere, the effective access boundary may be much larger than the managed policy name suggests.

The key question is not only what the policy itself allows, but whether the same principal can reach GuardDuty through other attached policies, roles, permission boundaries, or account-level access paths. AWS IAM Policies and Roles Guide is useful context for understanding how AWS evaluates permissions and where broader access can silently override the apparent limits of a single managed policy.

How It Fits GuardDuty Operations

In practice, this policy supports analysts, security engineers, and auditors who need to review GuardDuty output without the ability to alter detectors, suppress activity, or change monitoring posture. That makes it useful in separation-of-duties models, where visibility should not imply control.

It also fits the normal AWS operating model for delegated review. A team may need to inspect findings across accounts or regions, but the authority to enable, disable, or tune detection should remain with a smaller administrative group. The policy therefore supports operational transparency while limiting the chance of configuration drift.

For a broader view of how cloud identities and roles are commonly used to deliver that kind of access, Cloud Workload Identity Guide helps place AWS access patterns in the larger identity and access model.

What To Check Before Relying On It

Before using this managed policy as your only control, confirm who the principal is, what other policies are attached, and whether the role can assume into a more privileged path. Read-only access should stay read-only across the full effective permission set, not just inside one named policy.

That review is especially important in environments with shared roles, delegated administration, or inherited permissions from groups and permission sets. If a principal can view GuardDuty but also modify security services elsewhere, the access model may create a false sense of containment. GuardDuty visibility should be paired with least-privilege design, not treated as a substitute for it.

Risk and Threat Considerations

Read-only policies are low-risk in isolation, but they can still expose sensitive security telemetry and become misleading when combined with broader access. The main danger is not the policy itself, but the mismatch between what it appears to allow and what the principal can actually do through other permissions.

Failure mechanism: An analyst role that includes this managed policy may also inherit write access through another policy, role assumption path, or permissive permissions boundary, allowing changes to GuardDuty or related security controls despite the read-only label.

Impact: That mismatch can let a compromised or over-privileged principal alter detection posture, suppress visibility, or use GuardDuty intelligence to improve lateral movement and evasion planning.

Practitioner Guidance

Why practitioners should care: Treat this policy as a visibility entitlement, not as proof of safe isolation. The practical question is whether the principal’s total effective access remains read-only across all attached policies and role paths.

What to watch for: Review for policy stacking, role chaining, and any adjacent permissions that could let the same principal modify detectors, findings workflows, or related cloud security settings. If those paths exist, the managed policy no longer represents the true access posture.

Related resources from NHI Mgmt Group

• AWS AmazonEKSMCPReadOnlyAccess Managed Policy
• AWS AdministratorAccess Managed Policy
• AWS AmazonBedrockFullAccess Managed Policy
• AWS AmazonBedrockLimitedAccess Managed Policy