CloudTrail Log Files S3 Bucket is Publicly Accessible

• Query id: bd0088a5-c133-4b20-b129-ec9968b16ef3
• Query name: CloudTrail Log Files S3 Bucket is Publicly Accessible
• Platform: Terraform
• Severity: High
• Category: Observability
• URL: Github

Description

CloudTrail Log Files S3 Bucket should not be publicly accessible
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - tf file

provider "aws" {
  region = "us-east-1"
}

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 3.0"
    }
  }
}

data "aws_caller_identity" "current" {}

resource "aws_cloudtrail" "foobar" {
  name                          = "tf-trail-foobar"
  s3_bucket_name                = aws_s3_bucket.b.id
  s3_key_prefix                 = "prefix"
  include_global_service_events = false
}

resource "aws_s3_bucket" "b" {
  bucket = "my-tf-test-bucket"
  acl    = "public-read"

  tags = {
    Name        = "My bucket"
    Environment = "Dev"
  }
}

Positive test num. 2 - tf file

variable "aws_access_key" {}
variable "aws_secret_key" {}
variable "private_key_path" {}
variable "key_name" {}
variable "region" {
  default = "us-west-2"
}
provider "aws" {
  access_key = var.aws_access_key
  secret_key = var.aws_secret_key
  region     = var.region
}

module "s3_bucket" {
  source  = "terraform-aws-modules/s3-bucket/aws"
  version = "3.7.0"

  versioning = {
    enabled = true
  }

  bucket = "my_bucket"
  acl    = "public-read"
}

Positive test num. 3 - tf file

terraform {
  required_providers {
    aws = {
      source = "hashicorp/aws"
      version = "4.2.0"
    }
  }
}

provider "aws" {
  # Configuration options
}


module "s3_bucket" {
  source  = "terraform-aws-modules/s3-bucket/aws"
  version = "3.7.0"

  versioning = {
    enabled = true
  }

  bucket = "my_bucket"
  acl    = "public-read"
}

resource "aws_cloudtrail" "foobar2" {
  name                          = "tf-trail-foobar"
  s3_bucket_name                = aws_s3_bucket.bb.id
  s3_key_prefix                 = "prefix"
  include_global_service_events = false
}

resource "aws_s3_bucket" "bb" {
  bucket = "my-tf-test-bucket"
}

resource "aws_s3_bucket_acl" "example_bucket_acl" {
  bucket = aws_s3_bucket.bb.id
  acl    = "public-read"
}

Code samples without security vulnerabilities

Negative test num. 1 - tf file

provider "aws" {
  region = "us-east-1"
}

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 3.0"
    }
  }
}

data "aws_caller_identity" "current2" {}

resource "aws_cloudtrail" "foobar2" {
  name                          = "tf-trail-foobar"
  s3_bucket_name                = aws_s3_bucket.b2.id
  s3_key_prefix                 = "prefix"
  include_global_service_events = false
}

resource "aws_s3_bucket" "b2" {
  bucket = "my-tf-test-bucket"
  acl    = "private"

  tags = {
    Name        = "My bucket"
    Environment = "Dev"
  }
}

Negative test num. 2 - tf file

terraform {
  required_providers {
    aws = {
      source = "hashicorp/aws"
      version = "4.2.0"
    }
  }
}

provider "aws" {
  # Configuration options
}

resource "aws_cloudtrail" "foobar4" {
  name                          = "tf-trail-foobar"
  s3_bucket_name                = aws_s3_bucket.bbb.id
  s3_key_prefix                 = "prefix"
  include_global_service_events = false
}

resource "aws_s3_bucket" "bb" {
  bucket = "my-tf-test-bucket"
}

resource "aws_s3_bucket_acl" "example_bucket_acl2" {
  bucket = aws_s3_bucket.bbb.id
  acl    = "private"
}