CIS Compliance for AWS

What is CIS Compliance?

CIS (Center for Internet Security) Compliance refers to the adherence to security best practices outlined by the CIS, a nonprofit organization that develops globally recognized security standards. These best practices are known as CIS Controls and CIS Benchmarks, which provide guidelines for securing various technologies and systems, including operating systems, cloud services, network devices, and software.

Key Aspects of CIS Compliance

• Implementation of Controls: Start by implementing the CIS Controls relevant to your organization's size and risk profile.
• Use CIS Benchmarks: Configure your systems and applications according to CIS Benchmarks.
• Regular Audits: Continuously monitor and audit your systems to ensure ongoing compliance with CIS recommendations.
• Automation Tools: Consider using CIS-CAT (CIS Configuration Assessment Tool) or other automation tools to assess and enforce compliance across your infrastructure.

Benefits of CIS Compliance

• Standardized Security: Ensures that your organization follows industry-recognized security best practices.
• Risk Reduction: Helps in reducing the attack surface by implementing critical security controls.
• Compliance with Other Standards: CIS Controls and Benchmarks often overlap with other compliance frameworks like PCI-DSS, NIST, and ISO, making it easier to achieve multiple compliance goals simultaneously.
• Improved Incident Response: By implementing CIS Controls, organizations are better equipped to detect, respond to, and recover from security incidents.

CIS Compliance for your AWS Infrastructure

1. Identity and Access Management (IAM)

• Root Account Protection: Ensure that the AWS root account is not used for everyday tasks and that Multi-Factor Authentication (MFA) is enabled for the root account.
• IAM Policies: Apply the principle of least privilege by ensuring that IAM policies grant the minimum permissions required for users, roles, and services.
• MFA for IAM Users: Require MFA for all IAM users with console access.
• Password Policies: Implement strong password policies for IAM users, including complexity requirements and password expiration.

2. Logging and Monitoring

• CloudTrail: Enable AWS CloudTrail across all regions to log all API activity in your AWS account. Ensure logs are sent to an S3 bucket with encryption and that the bucket is protected against deletion.
• CloudWatch: Set up CloudWatch to monitor critical metrics and create alarms for unusual activities or threshold breaches.
• VPC Flow Logs: Enable VPC Flow Logs to capture information about the IP traffic going to and from network interfaces in your VPC.

3. Networking

• Security Groups and NACLs: Ensure that your Security Groups and Network ACLs (NACLs) are configured to allow only necessary traffic. Review and restrict inbound and outbound rules.
• Public Access to Resources: Avoid public access to sensitive resources. Ensure that no security groups allow unrestricted access (e.g., 0.0.0.0/0) unless explicitly required and monitored.
• Bastion Hosts: Use bastion hosts for SSH or RDP access to instances, ensuring that they are the only publicly accessible resources and are tightly controlled.

4. Encryption

• S3 Bucket Encryption: Ensure that all S3 buckets use server-side encryption (SSE) to protect data at rest. Enable default encryption for all new buckets.
• RDS and EBS Encryption: Enable encryption for Amazon RDS databases and Amazon EBS volumes, both for data at rest and backups.
• Key Management Service (KMS): Use AWS KMS to manage and rotate encryption keys. Ensure that access to KMS keys is restricted and monitored.

5. Auditing and Assessment Tools

• AWS Config: Use AWS Config to assess, audit, and evaluate the configurations of your AWS resources. Set up rules to automatically check for compliance with CIS benchmarks and trigger alerts for non-compliance.
• AWS Security Hub: Enable AWS Security Hub to aggregate security findings and compare them against CIS Benchmarks. Security Hub can also automatically generate compliance reports.
• CIS-CAT Tool: Use the CIS Configuration Assessment Tool (CIS-CAT) to automate the assessment of your AWS environment against the CIS Benchmarks.

6. Automation and Continuous Compliance

• Infrastructure as Code (IaC): Use tools like Pulumi to define your infrastructure in code. This allows you to apply CIS-compliant configurations consistently and easily across your environments.
• Automated Remediation: Implement automated remediation for non-compliant resources using AWS Lambda or AWS Config rules to enforce compliance.
• Continuous Monitoring: Regularly monitor your environment with tools like AWS Config, CloudWatch, and GuardDuty to ensure ongoing compliance with CIS benchmarks.

7. Documentation and Reporting

• Compliance Documentation: Maintain documentation of your CIS compliance efforts, including configurations, policies, and monitoring setups.
• Regular Audits: Schedule regular internal audits to review your configurations against the CIS benchmarks and update them as needed.