Streamlining Least Privilege with AWS IAM Access Analyzer's Unused Access
Adhering to the principle of least privilege is a fundamental security best practice that ensures users and roles have only the necessary permissions to perform their intended tasks. However, managing and refining permissions across an organization's AWS resources can be a daunting challenge, especially as environments evolve and access requirements change over time.
Amazon Web Services (AWS) recently introduced the Unused Access feature in IAM Access Analyzer, a powerful tool designed to simplify the inspection of unused access and guide organizations towards achieving least privilege.
The Principle of Least Privilege
The principle of least privilege is a cornerstone of cybersecurity, and a key pillar in the Zero trust Architecture, that aims to limit unintended access and track who has access to what resources. By granting only the minimum required permissions, organizations can significantly reduce the risk of unauthorized access and potential data breaches. However, implementing and maintaining least privilege is an ongoing process, as access requirements can change dynamically as applications and environments evolve.
For example, consider a developer group initially granted access to Amazon Elastic Compute Cloud (EC2) for their workloads. As the application modernizes and shifts to leveraging Amazon Elastic Container Service (ECS), the EC2 permissions may become redundant. In such scenarios, it is crucial to identify and refine the permissions of the dev team to remove the unnecessary EC2 access, ensuring they operate with the least privilege required for their current workloads.
The Challenge of Detecting and Remediating Unused Access
Addressing the verification and refinement of permissions is a challenging process, especially in large and complex AWS environments. Manually reviewing and auditing access across numerous resources, roles, and users can be time-consuming and error-prone. This is where AWS IAM Access Analyzer's Unused Access feature comes into play, providing organizations with a streamlined and automated approach to detecting and subsequently remediating unused access.
How Access Analyzer Works
IAM Access Analyzer continuously monitors and organizes unused access findings into a centralized summary dashboard. This dashboard provides a visual breakdown of all unused access findings by type, including unused roles, unused credentials (access keys), and unused permissions. Security teams can quickly gain a bird's-eye view of the findings per account within the AWS organization, enabling them to prioritize their remediation efforts effectively.
To enable unused access findings for your organization, you need to create an analyzer using the IAM Access Analyzer console or APIs in your management account or a delegated administrator account. The analyzer can be configured to monitor individual accounts or the entire AWS organization.
During the analyzer creation process, you can specify a tracking period, which is the threshold beyond which IAM Access Analyzer considers access to be unused. For example, if you set a tracking period of 90 days, the analyzer will highlight roles or permissions that have not been used within the last 90 days.
Investigating Unused Access Findings
Once the analyzer is set up, IAM Access Analyzer starts monitoring roles and users, looking for permissions that are granted but not actually used. The findings are then presented in the summary dashboard, allowing security teams to investigate and take appropriate actions.
- Unused Credentials (Access Keys)
IAM Access Analyzer identifies unused access keys for IAM users, providing details such as the creation date and the last use date for each access key. Security teams can review these findings and determine whether the access keys should be retained or deleted, helping to mitigate the risk of unauthorized access. - Unused Permissions
For findings related to unused permissions, IAM Access Analyzer displays the services and the list of permissions within those services that were not used by the role during the tracking period. This granular information empowers security teams to investigate with development teams and determine if those permissions are still required or can be removed, aligning with the principle of least privilege.
Automated Workflows and Integration
IAM Access Analyzer integrates seamlessly with other AWS services to streamline the remediation process. Unused access findings are sent as events to Amazon EventBridge, enabling organizations to create automated workflows and notification mechanisms. Additionally, these findings can be sent to AWS Security Hub, where they can be incorporated into the analysis of the organization's overall security posture.