Role with privilege escalation by actions 'lambda:CreateFunction' and 'iam:PassRole' and 'lambda:InvokeFunction'

Docs > Datadog Security > Code Security > Infrastructure as Code (IaC) Security > IaC Security Rules > Role with privilege escalation by actions 'lambda:CreateFunction' and 'iam:PassRole' and 'lambda:InvokeFunction'

Metadata

Id: terraform-aws-role-with-privilege-escalation-by-actions-iam-passrole-and-lambda-createfunction-lambda-invokefunction

Provider: AWS

Platform: Terraform

Severity: Medium

Category: Access Control

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Provider Reference

Description

This configuration grants an IAM role permission to create and invoke Lambda functions (lambda:CreateFunction and lambda:InvokeFunction), and to pass any IAM role (iam:PassRole) with the resource set to "*". This combination of permissions enables privilege escalation, as a user with these rights can create a Lambda function that assumes any role in the account, including high-privilege roles such as Administrator. The attacker could then execute arbitrary actions with elevated privileges by passing critical roles to their malicious Lambda and invoking it. If left unaddressed, this vulnerability could allow unauthorized access to sensitive resources or full account takeover.

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_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 = [
          "lambda:CreateFunction",
          "lambda:InvokeFunction"
        ]
        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 = "*"
      },
    ]
  })
}