Securing AWS Control Tower

Multi-Account AWS Security Baselines

AWS Control Tower automates the setup of a multi-account organization, but hardening the structure requires implementing advanced service control policies and centralized security guardrails. This guide outlines key security baselines.

1. Restricting Member Regions via SCPs

Deploy Service Control Policies (SCPs) at the root level of AWS Organizations to restrict API operations outside authorized regions. This blocks shadow IT and reduces your attack surface.

2. Centralized Security Logging

Route all AWS CloudTrail and VPC Flow Logs from member accounts into a dedicated, write-once-read-many (WORM) Log Archive account. Protect the bucket with AWS KMS customer-managed keys (CMK).

3. Implementing Least Privilege with IAM Identity Center

Migrate all user authentication to AWS IAM Identity Center (Single Sign-On). Enforce multi-factor authentication (MFA) and define granular Permission Sets to prevent privilege creep.