Ensure that AWS Lambda functions do not share the same AWS IAM execution role

Overview

It is recommended to have one IAM role per each Lambda function in order to follow the Principle of Least Privilege.

This way you can ensure that your Lambda functions will have the minimum privileges needed to perform the required tasks.

Remediation guidance

AWS remediation

Console

Identify Lambda functions sharing an execution role.
Create one least-privilege role per function.
Update each function to use its dedicated role.

AWS CLI

aws lambda update-function-configuration \
  --function-name <function-name> \
  --role arn:aws:iam::<account-id>:role/<dedicated-lambda-role>

References

https://docs.aws.amazon.com/lambda/latest/dg/lambda-intro-execution-role.html
https://docs.aws.amazon.com/cli/latest/reference/lambda/update-function-configuration.html

Multiple Remediation Paths

AWS

SERVICE-WIDE (RECOMMENDED when many resources are affected): Deploy centralized guardrails and remediation using AWS Config Conformance Packs and (if applicable) AWS Organizations SCPs.

aws configservice put-organization-conformance-pack --organization-conformance-pack-name <pack-name> --template-s3-uri s3://<bucket>/<template>.yaml

ASSET-LEVEL: Apply the resource-specific remediation steps above to only the affected assets.

PREVENTIVE: Add CI/CD policy checks (CloudFormation/Terraform validation) before deployment to prevent recurrence.

References for Service-Wide Patterns

AWS Config Conformance Packs: https://docs.aws.amazon.com/config/latest/developerguide/conformance-packs.html
AWS Organizations SCP examples: https://docs.aws.amazon.com/organizations/latest/userguide/orgs_manage_policies_scps_examples.html

Operational Rollout Workflow

Use this sequence to reduce risk and avoid repeated drift.

1. Contain at Service-Wide Scope First (Recommended)

AWS: deploy/adjust organization conformance packs and policy guardrails.

aws configservice put-organization-conformance-pack --organization-conformance-pack-name <pack-name> --template-s3-uri s3://<bucket>/<template>.yaml

2. Remediate Existing Affected Assets

Execute the control-specific Console/CLI steps documented above for each flagged resource.
Prioritize internet-exposed and production assets first.

3. Validate and Prevent Recurrence

Re-scan after each remediation batch.
Track exceptions with owner and expiry date.
Add preventive checks in IaC/CI pipelines.

Query logic

These are the stored checks tied to this control.

AWS Lambda functions do not share the same AWS IAM execution role

Connectors

AWS

Covered asset types

Function

Expected check: eq []

{AWSIAM21{...AssetFragment}}