ACM certificates should not use wildcard certificates¶

Ensure that ACM single domain name certificates are used instead of wildcard certificates within your AWS account in order to follow security best practices and protect each domain/subdomain with its own unique private key.

How to fix¶

Attribute domain_name of aws_acm_certificate must be non-empty.

Implementation options¶

Choose the option that matches how you manage Terraform. All options satisfy this control.

Option 1: Open source module (terraform-aws-modules)¶

If you use terraform-aws-modules/acm/aws, configure the required module inputs to satisfy this control. You can later migrate to the compliance.tf module with minimal changes because it is compatible by design.

module "acm" {
  source  = "terraform-aws-modules/acm/aws"
  version = ">=6.0.0,<7.0.0"

  domain_name               = "example.com"
  subject_alternative_names = ["*.example.com"]
  wait_for_validation       = false
  zone_id                   = "Z1234567890ABC"
}

Option 2: Terraform AWS provider resources¶

If you manage resources directly, configure the relevant Terraform AWS provider resources to meet this control. See docs for the resources involved: aws_acm_certificate.

resource "aws_acm_certificate" "this" {
  domain_name       = "example.com"
  validation_method = "DNS"
}

Tool mappings¶

Use these identifiers to cross-reference this control across tools, reports, and evidence.

• Compliance.tf (CTF) Control: acm_certificate_no_wildcard_domain_name

• Powerpipe Control: aws_compliance.control.acm_certificate_no_wildcard_domain_name