AI Summary: The terraform-aws-secure-baseline module automates the establishment of a secure configuration baseline for AWS accounts, adhering to recognized security benchmarks such as CIS AWS Foundations and AWS Foundational Security Best Practices. Key features include enhanced Identity and Access Management through IAM policies and roles, comprehensive logging and monitoring via AWS CloudTrail and CloudWatch, and secure networking configurations that limit exposure and enforce best practices. This module is integral for organizations seeking to enhance their security posture in AWS by simplifying compliance with security standards.

README

terraform-aws-secure-baseline

Terraform Module Registry

A terraform module to set up your AWS account with the reasonably secure configuration baseline. Most configurations are based on CIS Amazon Web Services Foundations v1.4.0 and AWS Foundational Security Best Practices v1.0.0.

See Benchmark Compliance to check which items in various benchmarks are covered.

Features

Identity and Access Management

• Set up IAM Password Policy.
• Create an IAM role for contacting AWS support for incident handling.
• Enable AWS Config rules to audit root account status.
• Enable IAM Access Analyzer in each region.
• Enable S3 account-level Public Access Block configuration.

Logging & Monitoring

• Enable CloudTrail in all regions and deliver events to CloudWatch Logs.
• Object-level logging for all S3 buckets is enabled by default.
• CloudTrail Insights event logging is enabled by default.
• CloudTrail logs are encrypted using AWS Key Management Service.
• All logs are stored in the S3 bucket with access logging enabled.
• Logs are automatically archived into Amazon Glacier after the given period(defaults to 90 days).
• Set up CloudWatch alarms to notify you when critical changes happen in your AWS account.
• Enable AWS Config in each regions to automatically take configuration snapshots.
• Enable SecurityHub and subscribe available standards.
• Enable GuardDuty in each regions.

Networking & Computing

• Remove all rules associated with default route tables, default network ACLs and default security groups in the default VPC in all regions.
• Disable automatic public IP assignments in default subnets.
• Enable AWS Config rules to audit unrestricted common ports in Security Group rules.
• Enable VPC Flow Logs with the default VPC in all regions.
• Enable default EBS encryption for newly created volumes.

Usage

data "aws_caller_identity" "current" {}
data "aws_region" "current" {}

module "secure_baseline" {
  source = "nozaq/secure-baseline/aws"

  audit_log_bucket_name           = "YOUR_BUCKET_NAME"
  aws_account_id                  = data.aws_caller_identity.current.account_id
  region                          = data.aws_region.current.name
  support_iam_role_principal_arns = ["YOUR_IAM_USER"]

  providers = {
    aws                = aws
    aws.ap-northeast-1 = aws.ap-northeast-1
    aws.ap-northeast-2 = aws.ap-northeast-2
    aws.ap-northeast-3 = aws.ap-northeast-3
    aws.ap-south-1     = aws.ap-south-1
    aws.ap-southeast-1 = aws.ap-southeast-1
    aws.ap-southeast-2 = aws.ap-southeast-2
    aws.ca-central-1   = aws.ca-central-1
    aws.eu-central-1   = aws.eu-central-1
    aws.eu-north-1     = aws.eu-north-1
    aws.eu-west-1      = aws.eu-west-1
    aws.eu-west-2      = aws.eu-west-2
    aws.eu-west-3      = aws.eu-west-3
    aws.sa-east-1      = aws.sa-east-1
    aws.us-east-1      = aws.us-east-1
    aws.us-east-2      = aws.us-east-2
    aws.us-west-1      = aws.us-west-1
    aws.us-west-2      = aws.us-west-2
  }
}

Check the example to understand how these providers are defined. Note that you need to define a provider for each AWS region and pass them to the module. Currently this is the recommended way to handle multiple regions in one module. Detailed information can be found at Providers within Modules - Terraform Docs.

A new S3 bucket to store audit logs is automatically created by default, while the external S3 bucket can be specified. It is useful when you already have a centralized S3 bucket to store all logs. Please see external-bucket example for more detail.

Managing multiple accounts in AWS Organization

When you have multiple AWS accounts in your AWS Organization, secure-baseline module configures the separated environment for each AWS account. You can change this behavior to centrally manage security information and audit logs from all accounts in one master account. Check organization example for more detail.

Submodules

This module is composed of several submodules and each of which can be used independently. Modules in Package Sub-directories - Terraform describes how to source a submodule.

• alarm-baseline
• analyzer-baseline
• cloudtrail-baseline
• config-baseline
• ebs-baseline
• guardduty-baseline
• iam-baseline
• s3-baseline
• secure-bucket
• securityhub-baseline
• vpc-baseline

Compatibility

• Starting from v1.0, this module requires Terraform Provider for AWS v4.0 or later. Version 1.0 Upgrade Guide described the recommended procedure after the upgrade.
• Starting from v0.20, this module requires Terraform Provider for AWS v3.0 or later. Please use v0.19 if you need to use v2.x or earlier.
• Starting from v0.10, this module requires Terraform v0.12 or later. Please use v0.9 if you need to use Terraform v0.11 or ealier.

Requirements

Providers

Inputs

list(object({
    account_id = string
    email      = string
  }))

Outputs