S3 Bucket Allows Public ACL

  • Query id: 48f100d9-f499-4c6d-b2b8-deafe47ffb26
  • Query name: S3 Bucket Allows Public ACL
  • Platform: CloudFormation
  • Severity: Medium
  • Category: Access Control
  • URL: Github

Description

S3 bucket allows public ACL
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - yaml file
Resources:
  Bucket11:
    Type: AWS::S3::Bucket
    Properties:
---
Resources:
  Bucket12:
    Type: AWS::S3::Bucket
    Properties:
      PublicAccessBlockConfiguration:
        BlockPublicPolicy     : true
        IgnorePublicAcls      : true
        RestrictPublicBuckets : true
---
Resources:
  Bucket13:
    Type: AWS::S3::Bucket
    Properties:
      PublicAccessBlockConfiguration:
        BlockPublicAcls: false
        BlockPublicPolicy     : true
        IgnorePublicAcls      : true
        RestrictPublicBuckets : true
Positive test num. 2 - json file
{
  "Resources": {
    "Bucket1": {
      "Type": "AWS::S3::Bucket",
      "Properties": {
        "PublicAccessBlockConfiguration": {
          "BlockPublicAcls": false,
          "BlockPublicPolicy": true,
          "IgnorePublicAcls": true,
          "RestrictPublicBuckets": true
        },
        "AccessControl": "Private"
      }
    }
  }
}

Code samples without security vulnerabilities

Negative test num. 1 - yaml file
Resources:
  Bucket1:
    Type: AWS::S3::Bucket
    Properties:
      PublicAccessBlockConfiguration:
        BlockPublicAcls       : true
        BlockPublicPolicy     : true
        IgnorePublicAcls      : true
        RestrictPublicBuckets : true
Negative test num. 2 - json file
{
  "Resources": {
    "Bucket1": {
      "Type": "AWS::S3::Bucket",
      "Properties": {
        "PublicAccessBlockConfiguration": {
          "BlockPublicAcls": true,
          "BlockPublicPolicy": true,
          "IgnorePublicAcls": true,
          "RestrictPublicBuckets": true
        },
        "AccessControl": "Private"
      }
    }
  }
}