What should be used instead of the AWS AmazonBedrockFullAccess managed policy for least privilege?

What “least privilege” should look like for Amazon Bedrock

The right replacement for AmazonBedrockFullAccess is a policy that matches the exact Bedrock capability in use, not the full service surface. For most workloads, that means allowing only the model invocation and related read actions the application truly needs, then narrowing resources, regions, and surrounding dependencies such as network paths or data stores. AWS IAM Policies and Roles Guide

In practice, the goal is to separate “can call Bedrock” from “can do anything in Bedrock.” A narrow policy should support the specific inference flow, the specific model or model family, and any required support actions without granting broad administrative or exploratory access. If the workload only submits prompts and receives completions, it should not inherit permissions for unrelated console activity or account-wide discovery.

That usually means starting from a deny-by-default posture and then adding back only the permissions needed for the workload’s path through the service. For example, if the application uses a single model, the policy should be anchored to that model scope rather than wildcarding every model resource. If it uses retrieval, agents, or knowledge bases, those adjacent permissions should be added deliberately and separately, not bundled into a blanket managed policy. Authorisation Models Guide

Where least privilege breaks down in Bedrock deployments

The main failure mode is treating a managed policy as a convenience layer instead of an access boundary. Broad policies make it easy for a workload to call more models, more actions, or more resources than the application path requires, which increases blast radius if prompts, credentials, or the integration itself are abused. That is especially important in workloads that can also touch customer data, internal documents, or downstream automation.

Another common issue is permission creep after the first deployment. A team adds one extra Bedrock action to fix a broken feature, then never revisits the policy when the workflow changes. Over time, the permission set becomes broader than the code path, and no one can tell whether every allowed action is still necessary. Ultimate Guide to NHIs, Key Challenges and Risks

Supporting dependencies can also widen exposure if they are not reviewed alongside the Bedrock permissions themselves. If a workload can reach storage buckets, secrets, or other services that feed prompts or store outputs, the effective privilege is larger than the IAM policy alone suggests. Least privilege only works when the surrounding trust path is reviewed as a whole, not when the Bedrock statement is tuned in isolation. Cloud PAM and CIEM Guide

How to replace AmazonBedrockFullAccess without breaking the workload

Build the replacement policy from the workload’s actual call pattern. Identify which Bedrock API actions are required, which resources they must target, and whether the application needs read-only access, invocation access, or a small set of adjacent operations. Then test the policy in the smallest environment that reproduces production behaviour before expanding it.

Use review points that track application change, not calendar habit alone. If the prompt workflow changes, the model set changes, or a new retrieval or agent step is introduced, re-check the policy before deployment. That is the point at which least privilege either stays accurate or starts to drift. Just-in-Time Access and Zero Standing Privilege Guide

If a team is unsure whether a permission is needed, treat that as a design signal, not a reason to keep the broad managed policy. The safer pattern is to add one permission, observe whether the workload still functions, and keep only what the application can justify. For AWS IAM generally, that approach is easier to maintain when policy logic is explicit and documented rather than hidden inside an all-purpose managed policy. AWS IAM Policies and Roles Guide

Risk and Threat Considerations

A broad managed policy increases the damage potential of credential theft, prompt injection into an agentic workflow, or a compromised integration that can call Bedrock on the attacker’s behalf. If the policy also reaches into surrounding data and service dependencies, the impact can extend well beyond model invocation to data exposure, unauthorized automation, or costly abuse of paid inference capacity.

Failure mechanism: Overbroad permissions let a workload exercise Bedrock actions, resources, or adjacent services that are not required for its intended function, so misuse or compromise has a much larger blast radius.

Impact: The result can be data exposure, unauthorized model use, unexpected downstream actions, and a harder incident response because the application had more standing access than it needed.

Practitioner Guidance

What to verify: Confirm the exact Bedrock actions in use, then compare them with the policy’s resource scope and any attached permissions to storage, secrets, or eventing services. If the workload never needs a console-style capability, do not grant one just because the managed policy includes it.

What to measure: Track how many allowed actions remain unused in production and how often policy edits are needed to restore functionality after application changes. A healthy result is a short, stable permission set that changes only when the workload’s behaviour changes.

Practitioner takeaway: The best replacement for AmazonBedrockFullAccess is not another broad Bedrock policy, it is a narrowly documented permission set that matches the workload’s exact model and dependency path.

Related resources from NHI Mgmt Group

• What should be used instead of the AWS AmazonBedrockLimitedAccess managed policy for least privilege?
• What should be used instead of the AWS AmazonDynamoDBFullAccess managed policy for least privilege?
• What should be used instead of the AWS AmazonBedrockReadOnly managed policy for least privilege?
• What should be used instead of the AWS AmazonEKSVPCResourceController managed policy for least privilege?