Grant least privilege access

Granting least privilege access is a best practice that ensures identities are only granted the minimal access required to perform specific actions on specific resources, under specific conditions. By limiting access, you reduce the potential attack surface and ensure tighter security. Using group-based permissions and identity attributes allows for scalable access control, dynamically adjusting access without the need to modify individual policies.

1. Grant only the necessary permissions: Define permissions that allow identities (human or machine) to perform only the actions they require on the resources they need to access. Avoid granting broad or excessive permissions that may expose more resources than necessary.
2. Use group-based permissions: Instead of managing permissions at the individual user level, assign users to groups based on their roles or projects. Manage permissions at the group level to simplify administration and ensure that when a user’s role changes, their access is automatically adjusted without requiring policy updates.
3. Leverage identity attributes for dynamic access control: Use identity attributes such as department, job role, or project membership to dynamically assign permissions. For example, a group of developers could be allowed to manage only the resources for their project. When a developer leaves the project, their access is automatically revoked without altering the underlying policies.
4. Set conditional access controls: Implement conditions that further limit access based on factors such as time, location, or device. This ensures that even when access is granted, it is only used under the specified conditions, minimizing the risk of unauthorized access.
5. Review and adjust permissions regularly: Periodically review access policies to ensure they remain aligned with the principle of least privilege. As users change roles or projects, their permissions should be adjusted accordingly to avoid unnecessary access.

Supporting Questions:

• How do you ensure that permissions are restricted to only what is necessary for each identity?
• What processes are in place to assign and manage group-based permissions?
• How do you handle access adjustments when users change roles or leave a project?

Roles and Responsibilities:

Identity and Access Management Specialist:

• Responsibilities:
  • Design and implement least privilege access policies based on role-based or attribute-based access control.
  • Regularly audit and review access policies to ensure they remain aligned with the least privilege principle.
  • Use identity attributes to dynamically adjust permissions at scale.

Cloud Administrator:

• Responsibilities:
  • Apply and manage group-based access controls using AWS Identity and Access Management (IAM).
  • Configure conditional access controls to limit when and how users can access resources.
  • Monitor access logs to ensure that permissions are used as intended and adjust as needed.

Artefacts:

• Least Privilege Policy Documentation: Detailed access control policies specifying the minimal permissions required for each role or group.
• Group Membership and Attribute Records: Documentation showing how user groups and attributes are used to assign permissions dynamically.
• Access Review Reports: Reports generated from periodic audits that review current permissions against least privilege principles to ensure compliance.

Relevant AWS Services:

AWS Identity Services:

• AWS Identity and Access Management (IAM): Allows you to define least privilege access by creating fine-grained policies that specify which actions and resources an identity can access.
• AWS Organizations with Service Control Policies (SCPs): Used to enforce least privilege access across AWS accounts, ensuring that permissions do not exceed defined limits for users and services.
• AWS Single Sign-On (SSO): Enables centralized management of permissions using group-based access control, ensuring that users have the least privilege necessary for their role.

Monitoring and Compliance Services:

• AWS CloudTrail: Logs all access attempts and actions on AWS resources, allowing you to monitor the effectiveness of least privilege policies and detect potential issues.
• AWS Config: Tracks changes to IAM policies and permissions to ensure compliance with least privilege best practices. It helps in identifying any drift or over-permissioned identities.