Role With Privilege Escalation By Actions 'ec2:RunInstances' And 'iam:PassRole'

• Query id: 30b88745-eebe-4ecb-a3a9-5cf886e96204
• Query name: Role With Privilege Escalation By Actions 'ec2:RunInstances' And 'iam:PassRole'
• Platform: Terraform
• Severity: Medium
• Category: Access Control
• CWE: 269
• URL: Github

Description

Role with privilege escalation by actions 'ec2:RunInstances' and 'iam:PassRole' and Resource set to '*'. For more information see https://rhinosecuritylabs.com/aws/aws-privilege-escalation-methods-mitigation/.
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - tf file

resource "aws_iam_role" "cosmic" {
  name = "cosmic"
}

resource "aws_iam_role_policy" "test_inline_policy" {
  name = "test_inline_policy"
  role = aws_iam_role.cosmic.name

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


resource "aws_iam_policy_attachment" "test-attach" {
  name       = "test-attachment"
  roles      = [aws_iam_role.cosmic.name]
  policy_arn = aws_iam_policy.policy.arn
}


resource "aws_iam_policy" "policy" {
  name        = "test-policy"
  description = "A test policy"

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

Code samples without security vulnerabilities

Negative test num. 1 - tf file

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 = "*"
      },
    ]
  })
}