User with privilege escalation by actions 'iam:PutGroupPolicy'

This product is not supported for your selected Datadog site. ().

Metadata

Id: 8bfbf7ab-d5e8-4100-8618-798956e101e0

Cloud Provider: AWS

Platform: Terraform

Severity: Medium

Category: Access Control

Learn More

Description

Granting an IAM user the iam:PutGroupPolicy action with "Resource": "*" allows them to attach arbitrary inline policies to any IAM group in the AWS account, leading to potential privilege escalation. With this permission, a user could assign powerful or administrative permissions to groups they belong to, effectively bypassing intended security boundaries. To prevent this, it’s important to restrict IAM user actions to the minimum necessary and avoid using wildcards in sensitive permissions, as shown below:

policy = jsonencode({
  Version = "2012-10-17"
  Statement = [
    {
      Action = [
        "ec2:Describe*",
      ]
      Effect   = "Allow"
      Resource = "*"
    },
  ]
})

Compliant Code Examples

resource "aws_iam_user" "cosmic2" {
  name = "cosmic2"
}

resource "aws_iam_user_policy" "inline_policy_run_instances2" {
  name = "inline_policy_run_instances"
  user = aws_iam_user.cosmic2.name

  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Action = [
          "ec2:Describe*",
        ]
        Effect   = "Allow"
        Resource = "*"
      },
    ]
  })
}

Non-Compliant Code Examples

resource "aws_iam_user" "cosmic" {
  name = "cosmic"
}

resource "aws_iam_user_policy" "test_inline_policy" {
  name = "test_inline_policy"
  user = aws_iam_user.cosmic.name

  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Action = [
          "iam:PutGroupPolicy",
        ]
        Effect   = "Allow"
        Resource = "*"
      },
    ]
  })
}


resource "aws_iam_policy_attachment" "test-attach" {
  name       = "test-attachment"
  users      = [aws_iam_user.cosmic.name]
  roles      = [aws_iam_role.role.name]
  groups     = [aws_iam_group.group.name]
}