Rule: Ensure IAM Users are Managed Centrally

Managing IAM users centrally through identity federation or AWS Organizations helps maintain a secure and scalable multi-account AWS environment. Centralized management provides better security oversight, reduces administrative overhead, and helps enforce consistent policies across all accounts. For compliance with the Center for Internet Security (CIS) benchmarks, specifically version 1.5.0, here's a detailed description of the rule and remediation steps.

This rule enforces that all AWS Identity and Access Management (IAM) users should be managed centrally. Centralized management means that user identities are not created and managed individually within each AWS account but are controlled through a single identity source. This source can be either an external identity provider (IdP) that supports SAML 2.0 (such as Microsoft Active Directory Federation Services) or AWS Organizations for managing multiple AWS accounts.

• Consistency in access control across accounts
• Simplified management of permissions and roles
• Easier audit and compliance checks
• Streamlined user provisioning and de-provisioning

If users aren't centrally managed, it could be due to:

• Duplicate IAM users across accounts
• Individual IAM users created instead of federated access
• No enablement of AWS Organizations or SSO

To troubleshoot, you need to:

• Ensure you have access to an external IdP, like Active Directory or an equivalent service that supports SAML 2.0.

• Set up SAML assertions to map IdP attributes and groups to AWS IAM roles and permissions.

• Use the AWS CLI to create the SAML provider, replacing

  IdP-name

  and the XML document with your own details.

• Use AWS SSO if available, to manage access centrally to multiple AWS accounts and applications.

• Assign SSO to groups in your IdP that correspond to policies in AWS IAM for seamless access management.

• Use the AWS Management Console to create an organization from the

  AWS Organizations

  console or via AWS CLI:

• Invite existing AWS accounts or create new ones within your organization.

• Apply SCPs across your organization to enforce permissions for IAM users.

• Manage user access to accounts in your organization via AWS Single Sign-On.

By following these steps, you can ensure that IAM user management aligns with CIS recommendations and improves your overall security posture. Automation with AWS CloudFormation or Terraform scripts can further streamline this process for large organizations.

Remember, implementing these best practices is not only crucial for security and compliance but it's also a sound business strategy that can bolster your organization's operational efficiency. If your organization reflects the utmost commitment to security best practices, you're more likely to inspire confidence in both your customers and employees.