---
title: S3 bucket ACL allows read to any authenticated user
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Infrastructure as Code (IaC)
  Security > IaC Security Rules > S3 bucket ACL allows read to any authenticated
  user
---

# S3 bucket ACL allows read to any authenticated user

{% callout %}
# Important note for users on the following Datadog sites: app.ddog-gov.com, us2.ddog-gov.com

{% alert level="danger" %}
This product is not supported for your selected [Datadog site](https://docs.datadoghq.com/getting_started/site.md). ({% placeholder "user-datadog-site-name" /%}).
{% /alert %}

{% /callout %}

## Metadata{% #metadata %}

**Id:** `cloudformation-aws-s3-bucket-acl-allows-read-to-any-authenticated-user` 

**Provider:** AWS

**Platform:** CloudFormation

**Severity:** High

**Category:** Access Control

#### Learn More{% #learn-more %}

- [Provider Reference](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-s3-bucket.html)

### Description{% #description %}

S3 buckets configured with the `AuthenticatedRead` canned ACL allow any AWS authenticated user to read bucket objects. This can lead to unintended data exposure and compliance violations. For CloudFormation, the `AWS::S3::Bucket` resource's `AccessControl` property must not be set to `AuthenticatedRead`. Resources with `AccessControl: AuthenticatedRead` will be flagged. Set `AccessControl: Private` or omit ACLs and enforce least-privilege access using explicit bucket policies or IAM principals instead.

Secure configuration example:

```yaml
MyBucket:
  Type: AWS::S3::Bucket
  Properties:
    BucketName: my-bucket
    AccessControl: Private
```

## Compliant Code Examples{% #compliant-code-examples %}

```yaml
AWSTemplateFormatVersion: 2010-09-09
Description: Creating S3 bucket
Resources:
  JenkinsArtifacts03:
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: BucketOwnerFullControl
      BucketName: jenkins-artifacts
      VersioningConfiguration:
        Status: Enabled
      Tags:
        - Key: CostCenter
          Value: ITEngineering
        - Key: Type
          Value: CICD
```

```yaml
AWSTemplateFormatVersion: 2010-09-09
Description: Creating S3 bucket
Resources:
  JenkinsArtifacts04:
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: Private
      BucketName: jenkins-secret-artifacts
      VersioningConfiguration:
        Status: Enabled
      Tags:
        - Key: CostCenter
          Value: ''
```

```yaml
AWSTemplateFormatVersion: 2010-09-09
Description: Creating S3 bucket
Resources:
  JenkinsArtifacts05:
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: PublicReadWrite
      BucketName: jenkins-secret-artifacts2
      VersioningConfiguration:
        Status: Enabled
      Tags:
        - Key: CostCenter
          Value: ITEngineering
```

## Non-Compliant Code Examples{% #non-compliant-code-examples %}

```yaml
AWSTemplateFormatVersion: 2010-09-09
Description: Creating S3 bucket
Resources:
  JenkinsArtifacts01:
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: AuthenticatedRead
      BucketName: jenkins-artifacts
      Tags:
        - Key: CostCenter
          Value: ITEngineering
```

```yaml
AWSTemplateFormatVersion: 2010-09-09
Description: Creating S3 bucket
Resources:
  StaticPage01:
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: AuthenticatedRead
      BucketName: public-read-static-page01
      WebsiteConfiguration:
        ErrorDocument: 404.html
        IndexDocument: index.html
      Tags:
        - Key: CostCenter
          Value: ITEngineering
```

```yaml
AWSTemplateFormatVersion: 2010-09-09
Description: Creating S3 bucket
Resources:
  JenkinsArtifacts02:
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: AuthenticatedRead
      BucketName: jenkins-artifacts-block-public
      PublicAccessBlockConfiguration:
        BlockPublicPolicy: false
      VersioningConfiguration:
        Status: Enabled
      Tags:
        - Key: CostCenter
          Value: ITEngineering
        - Key: Type
          Value: CICD
```