AWS S3 Bucket has the block public ACLs disabled misconfiguration detected in code

Rule Details

Cortex AppSec Rule ID	APPSEC_AWS_53
Category - Subcategory	Storage - Permissions
Provider	AWS
Severity	MEDIUM
Framework	CloudFormation, Serverless, Terraform, Terraform Plan

Impact

This rule ensures that Amazon S3 buckets have the block public ACLs setting enabled. Blocking public ACLs helps prevent the exposure of sensitive data by ensuring that public access permissions are not granted through ACLs. This setting is crucial for maintaining the security and privacy of the data stored in S3 buckets. This rule checks whether the BlockPublicAcls option is enabled in the PublicAccessBlockConfiguration of S3 buckets.

How to Fix

To fix this issue, ensure that the BlockPublicAcls property in the PublicAccessBlockConfiguration of the AWS::S3::Bucket resource is set to true.

Example: [source,go]

{ "Resources": { "MyS3Bucket": { "Type": "AWS::S3::Bucket", "Properties": { "BucketName": "example-bucket", "PublicAccessBlockConfiguration": { "BlockPublicAcls": true, ... } } } } }

Resources: MyS3Bucket: Type: AWS::S3::Bucket Properties: BucketName: example-bucket PublicAccessBlockConfiguration: BlockPublicAcls: true ...