KMS Key With Vulnerable Policy

• Query id: 7ebc9038-0bde-479a-acc4-6ed7b6758899
• Query name: KMS Key With Vulnerable Policy
• Platform: Terraform
• Severity: High
• Category: Insecure Configurations
• URL: Github

Description

Checks if the policy is vulnerable and needs updating.
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - tf file

resource "aws_kms_key" "positive1" {
  description             = "KMS key 1"
  deletion_window_in_days = 10

  policy = <<POLICY
  {
    "Version": "2012-10-17",
    "Statement":[
      {
        "Sid":"AddCannedAcl",
        "Effect":"Allow",
        "Principal": {"AWS":"*"},
        "Action":["kms:*"],
        "Resource":"*"
      }
    ]
  }
  POLICY
}

Positive test num. 2 - tf file

resource "aws_kms_key" "positive1" {
  description             = "KMS key 1"
  deletion_window_in_days = 10

  policy = <<POLICY
  {
    "Version": "2012-10-17",
    "Statement":[
      {
        "Sid":"AddCannedAcl",
        "Effect":"Allow",
        "Principal": "*",
        "Action":["kms:*"],
        "Resource":"*"
      }
    ]
  }
  POLICY
}

Positive test num. 3 - tf file

resource "aws_kms_key" "positive3" {
  description             = "KMS key 1"
  deletion_window_in_days = 10
}

Code samples without security vulnerabilities

Negative test num. 1 - tf file

resource "aws_kms_key" "negative1" {
  description             = "KMS key 1"
  deletion_window_in_days = 10

  policy = <<POLICY
  {
    "Version": "2012-10-17",
    "Statement":[
      {
        "Sid":"AddCannedAcl",
        "Effect":"Deny",
        "Principal": {"AWS": [
          "arn:aws:iam::111122223333:user/CMKUser"
        ]},
        "Action": [
          "kms:Encrypt",
          "kms:Decrypt",
          "kms:ReEncrypt*",
          "kms:GenerateDataKey*",
          "kms:DescribeKey"
        ],
        "Resource":"*"
      }
    ]
  }
  POLICY
}