Managing and securing multiple AWS accounts can be a daunting task, especially as organizations scale their cloud footprint. Without a streamlined governance model, security risks can proliferate, leading to compliance gaps and operational inefficiencies. In this post, weโ€™ll explore best practices for securing hundreds of AWS accounts while ensuring centralized governance and operational efficiency. ๐Ÿข๐Ÿ”โš™๏ธ

The Challenge of Managing Multiple AWS Accounts ๐Ÿคฏ๐Ÿ”Ž๐Ÿšจ

As organizations grow, so do their AWS environments. Companies often operate multiple AWS accounts for various reasons, such as application isolation, compliance requirements, and cost allocation. However, this expansion introduces security challenges, including:

  • Inconsistent security policies across accounts
  • Lack of centralized visibility into security events
  • Complicated IAM and access management
  • Difficulty in enforcing compliance

A well-structured approach to governance can help mitigate these challenges. ๐Ÿ›๏ธ๐Ÿ“โœ…

1. Implement AWS Organizations for Centralized Governance ๐Ÿข๐Ÿ“œ๐Ÿ”

AWS Organizations provides a hierarchical structure to manage multiple accounts under a single entity. This enables organizations to:

  • Apply Service Control Policies (SCPs) to enforce security baselines
  • Use Organizational Units (OUs) to categorize accounts by function (e.g., production, development, sandbox)
  • Enable consolidated billing for cost management

Best Practices:

  • Use OUs to group accounts logically and apply specific SCPs.
  • Restrict root user access across all accounts.
  • Implement mandatory MFA for all IAM users and roles. ๐Ÿ›ก๏ธโœ…๐Ÿ”‘

AWS CLI: Setting Up AWS Organizations ๐Ÿ—๏ธ๐Ÿ”ง๐Ÿ–ฅ๏ธ

aws organizations create-organization
aws organizations create-organizational-unit --parent-id r-235433899xxx --name Security
aws organizations attach-policy --target-id ou-4555xxxxxx --policy-id p-7889xxx

2. Enforce Security Policies with AWS Control Tower ๐Ÿ—๏ธ๐Ÿ”Ž๐Ÿ›ก๏ธ

AWS Control Tower simplifies multi-account governance by automating account provisioning and applying security guardrails. It integrates with AWS Organizations and provides:

  • Pre-configured guardrails for security and compliance
  • Baseline security configurations for new accounts
  • Centralized logging via AWS CloudTrail and AWS Config

Best Practices:

  • Leverage AWS Control Tower for setting up new AWS accounts with predefined security controls.
  • Enable AWS Config to monitor configuration drift across all accounts.
  • Use AWS Security Hub to get a unified view of security alerts. ๐Ÿ”„๐Ÿ”๐Ÿ“Š

AWS CLI: Deploying AWS Control Tower ๐Ÿข๐Ÿ› ๏ธ๐Ÿ–ฅ๏ธ

aws controltower enable-control --control-identifier AWS-GUARDRAIL-EXAMPLE --target-identifier ou-4555xxxxxx

3. Implement Centralized IAM and Access Management ๐Ÿ”๐Ÿ‘ฅ๐Ÿ“‚

Managing access across hundreds of accounts can become complex without a clear IAM strategy. Some key approaches include:

  • AWS IAM Identity Center (formerly AWS SSO): Enables centralized user access management across multiple accounts.
  • Least Privilege Principle: Restrict access to only necessary permissions.
  • Federated Authentication: Use an identity provider (IdP) such as Okta, Azure AD, or AWS IAM Identity Center.

Best Practices:

  • Enforce strong authentication policies (e.g., MFA, password policies).
  • Use IAM roles instead of IAM users to limit long-lived credentials.
  • Regularly audit IAM policies with AWS Access Analyzer. ๐Ÿ•ต๏ธโ€โ™‚๏ธโœ…๐Ÿ”Ž

AWS CLI: Configuring IAM Identity Center ๐Ÿข๐Ÿ”‘๐Ÿ› ๏ธ

aws sso-admin create-permission-set --instance-arn arn:aws:sso:::instance/ssoins-example1234 --name AdminAccess

4. Centralized Logging and Monitoring with AWS Security Services ๐Ÿ“œ๐Ÿ“Š๐Ÿš€

Security teams need visibility into activities across all AWS accounts. AWS provides several tools to centralize security monitoring:

  • AWS CloudTrail: Logs all API activity for auditing and compliance.
  • Amazon GuardDuty: Detects threats and anomalies across AWS workloads.
  • AWS Security Hub: Aggregates security findings from multiple AWS services.

Best Practices:

  • Enable CloudTrail across all accounts and store logs centrally in S3.
  • Use GuardDuty for continuous monitoring of malicious activity.
  • Set up AWS Security Hub to correlate security findings. ๐Ÿ”๐Ÿ“ˆ๐Ÿ›‘

AWS CLI: Setting Up AWS Security Hub ๐Ÿ”๐Ÿ› ๏ธ๐Ÿ“Š

aws securityhub enable-security-hub
aws securityhub create-insight --name "Unusual API Calls" --filters '{"Action":"Count","Operator":"GREATER_THAN","Value":10}'

5. Automate Compliance and Remediation ๐Ÿค–โš™๏ธโœ…

Maintaining compliance across a large AWS environment requires automation. AWS provides several tools to enforce security policies and automate remediation:

  • AWS Config Rules: Automatically check compliance against predefined rules.
  • AWS Lambda & EventBridge: Automate responses to security events.
  • AWS Systems Manager: Automate patch management and operational tasks.

Best Practices:

  • Define custom AWS Config rules to enforce security policies.
  • Use AWS Lambda to remediate misconfigurations automatically.
  • Implement patch automation for EC2 instances and containerized workloads. ๐Ÿ”„โšก๐Ÿ”

AWS CLI: Automating Compliance with AWS Config ๐Ÿ› ๏ธ๐Ÿ”๐Ÿค–

aws configservice put-config-rule --config-rule-name "restricted-ssh" --source Identifier=AWS-EBS-ENCRYPTION-BY-DEFAULT

Next Steps ๐Ÿš€๐Ÿ”Ž

Securing hundreds of AWS accounts requires a well-structured governance model that enforces consistency, enhances security visibility, and automates compliance. Hereโ€™s what you can do next:

โœ… Review your AWS account structure and governance model.
โœ… Implement security best practices using AWS Organizations, Control Tower, and IAM Identity Center.
โœ… Set up centralized logging and security monitoring.
โœ… Automate compliance and remediation with AWS Config and Lambda.
โœ… Continuously monitor and improve security posture.

REFRENECE

https://docs.aws.amazon.com/controltower/latest/userguide/getting-started-with-control-tower.html
https://www.youtube.com/watch?v=2J1xGKmnNQI
https://docs.aws.amazon.com/organizations/latest/userguide/orgs_tutorials_basic.html
https://docs.aws.amazon.com/images/whitepapers/latest/aws-security-incident-response-guide/images/incident-response-account-structure.png
https://docs.aws.amazon.com/securityhub/latest/userguide/securityhub-settingup.html