IAM Policy Document Allows All or Any AWS Principal Permissions to Resources

Description

This policy is checking to ensure that no Identity and Access Management (IAM) policy documents are allowing "ALL" or any AWS principal permissions to the resource. This is potentially harmful because it signifies that there are overly permissive policies in place. If all AWS principals have permission, it means any entity in AWS can potentially access or modify the resource, which can lead to unintended access, data leaks, or security breaches. Any security best practices recommend least privilege approach - the permission should only be given to the required and authorized entities.

Code Example

resource "aws_iam_policy" "example" {
  name        = "example_policy"
  path        = "/"
  description = "An example policy"

  policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
        "s3:ListBucket"
      ],
      "Effect": "Allow",
      "Resource": "arn:aws:s3:::example_bucket",
      "Principal": {
        "AWS": [
          "arn:aws:iam::ACCOUNT_ID:root"
        ]
      }
    }
  ]
}
EOF
}

Remediation

Terraform

• Resource: aws_iam_policy_document
• Arguments: statement

To fix this issue, you need to specify the principals in your IAM policy, instead of using wildcard "*". Additionally, regulate the actions that can be performed by each principal, instead of allowing all actions.

Rule Details

Field	Value
ID	IAC-0331
Severity	HIGH
IaC Type	Terraform
Frameworks	Terraform, TerraformPlan
Checkov ID	CKV_AWS_283

References

• Checkov Rule

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