Getting Started with Permissions Boundaries in AWS

Imagine you're setting up a playground. You want the kids to have fun and explore, but you also want to make sure they stay safe and don't wander off too far. In AWS, permission boundaries serve a similar purpose for your IAM (Identity and Access Management) users and roles.

Permission boundaries are advanced AWS features that help limit the maximum permissions IAM roles or users can have. They act as guardrails, defining the outermost limits of permissions for IAM entities, ensuring they cannot exceed the permissions you're comfortable granting.

Why Use Permission Boundaries?

1. Enhanced Security: They provide an additional layer of security by ensuring that even if an IAM policy grants broad permissions, the permission boundary can restrict what actions the user or role can actually perform.

2. Delegation with Control: Permission boundaries enable you to delegate permissions management to other users securely. You can allow teams to manage their IAM roles and users without worrying about them granting overly permissive or unintended permissions.

3. Compliance and Governance: They help maintain compliance and governance by ensuring that permissions are only as broad as they need to be, preventing privilege escalation and enforcing least privilege.

How to Set Up Permission Boundaries

Setting up permission boundaries is a straightforward process. Here's how you can do it in just a few steps:

Step 1: Create a Permission Policy

First, you need to create a permissions policy that defines the maximum permissions you want to allow. This policy acts as your permission boundary.

1. Go to the IAM dashboard in the AWS Management Console.
2. Navigate to "Policies" and click "Create policy".
3. Define the permissions in the visual editor or JSON tab. For example, you might want to allow everything ("*") but restrict access to deleting IAM roles.
4. Review and name your policy, then click "Create policy".

Step 2: Attach the Permission Boundary to an IAM Role or User

Once you have your permission boundary policy, you can attach it to a new or existing IAM role or user.

1. Go to the IAM dashboard.
2. Select "Roles" or "Users" and choose the role or user you want to modify.
3. In the details page, look for the "Add permission boundary" option.
4. Search and select the permission boundary policy you created.
5. Save your changes.

Best Practices

• Regularly Review: Make it a habit to regularly review your permission boundaries and IAM policies to ensure they still align with your security requirements.
• Principle of Least Privilege: Always start with minimal necessary permissions and gradually adjust as needed, rather than starting broad and narrowing down.
• Use Descriptive Names: When creating permission boundaries and policies, use names that clearly describe their purpose and scope.

Conclusion

Permission boundaries in AWS are a powerful tool for enhancing your cloud security, providing control over the maximum permissions that can be granted to IAM roles and users. By understanding and implementing permission boundaries, you can ensure a safer and more controlled AWS environment.