IAM Policies Attached To User

• Query id: b4378389-a9aa-44ee-91e7-ef183f11079e
• Query name: IAM Policies Attached To User
• Platform: Terraform
• Severity: Medium
• Category: Access Control
• URL: Github

Description

IAM policies should be attached only to groups or roles
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - tf file

resource "aws_iam_user" "positive1_1" {
  name          = "${local.resource_prefix.value}-user"
  force_destroy = true

  tags = {
    Name        = "${local.resource_prefix.value}-user"
    Environment = local.resource_prefix.value
  }

}

resource "aws_iam_access_key" "positive1_2" {
  user = aws_iam_user.user.name
}

resource "aws_iam_policy_attachment" "positive1_3" {
  name = "excess_policy"
  users = [aws_iam_user.user.name]

  policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
        "ec2:*",
        "s3:*",
        "lambda:*",
        "cloudwatch:*"
      ],
      "Effect": "Allow",
      "Resource": "*"
    }
  ]
}
EOF
}

output "username" {
  value = aws_iam_user.user.name
}

output "secret" {
  value = aws_iam_access_key.user.encrypted_secret
}

Positive test num. 2 - tf file

resource "aws_iam_user" "positive2_1" {
  name          = "${local.resource_prefix.value}-user"
  force_destroy = true

  tags = {
    Name        = "${local.resource_prefix.value}-user"
    Environment = local.resource_prefix.value
  }

}

resource "aws_iam_access_key" "positive2_2" {
  user = aws_iam_user.user.name
}

resource "aws_iam_user_policy" "positive2_3" {
  name = "excess_policy"
  user = aws_iam_user.user.name

  policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
        "ec2:*",
        "s3:*",
        "lambda:*",
        "cloudwatch:*"
      ],
      "Effect": "Allow",
      "Resource": "*"
    }
  ]
}
EOF
}

output "username" {
  value = aws_iam_user.user.name
}

output "secret" {
  value = aws_iam_access_key.user.encrypted_secret
}

Positive test num. 3 - tf file

resource "aws_iam_user" "user" {
  name = "test-user"
}

resource "aws_iam_policy" "policy" {
  name        = "test_policy"
  path        = "/"
  description = "My test policy"

  # Terraform's "jsonencode" function converts a
  # Terraform expression result to valid JSON syntax.
  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Action = [
          "ec2:Describe*",
        ]
        Effect   = "Allow"
        Resource = "*"
      },
    ]
  })
}

resource "aws_iam_user_policy_attachment" "test-attach" {
  user       = aws_iam_user.user.name
  policy_arn = aws_iam_policy.policy.arn
}

Code samples without security vulnerabilities

Negative test num. 1 - tf file

resource "aws_iam_user" "negative1" {
  name          = "${local.resource_prefix.value}-user"
  force_destroy = true

  tags = {
    Name        = "${local.resource_prefix.value}-user"
    Environment = local.resource_prefix.value
  }

}

resource "aws_iam_access_key" "negative2" {
  user = aws_iam_user.user.name
}

resource "aws_iam_policy_attachment" "negative3" {
  name = "excess_policy"

  policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
        "ec2:*",
        "s3:*",
        "lambda:*",
        "cloudwatch:*"
      ],
      "Effect": "Allow",
      "Resource": "*"
    }
  ]
}
EOF
}

output "username" {
  value = aws_iam_user.user.name
}

output "secret" {
  value = aws_iam_access_key.user.encrypted_secret
}