Ensure that your Amazon S3 buckets are not granting FULL_CONTROL access to authenticated users (i.e. signed AWS accounts or IAM users) in order to prevent unauthorized access. An Amazon S3 bucket that allows full control access to authenticated users will give any AWS account or IAM user the ability to LIST (READ) objects, UPLOAD/DELETE (WRITE) objects, VIEW (READ_ACP) objects permissions, and EDIT (WRITE_ACP) permissions for the objects within the bucket. Trend Micro Cloud One™ – Conformity strongly recommends against setting all these permissions for the "Authenticated users group (anyone with an AWS account)" grantee in production.
This rule can help you with the following compliance standards:
- PCI
- APRA
- MAS
- NIST4
For further details on compliance standards supported by Conformity, see here.
This rule can help you work with the AWS Well-Architected Framework.
This rule resolution is part of the Conformity Security & Compliance tool for AWS.
Granting authenticated FULL_CONTROL access to Amazon S3 buckets can allow other AWS accounts or IAM users to view, upload, modify, and delete S3 objects without any restrictions. Exposing your S3 buckets to other AWS signed accounts or IAM users can lead to data leaks, data loss, and unexpected charges on your AWS bill.
Audit
To determine if your Amazon S3 buckets allow full access to AWS authenticated users, perform the following operations:
Remediation / Resolution
To deny authenticated FULL_CONTROL access to your Amazon S3 buckets, perform the following operations:
Note: An S3 bucket can be deemed compliant if implements either "AccessControl": "Private" or sets the "PublicAccessBlockConfiguration" feature options to true. The following CloudFormation template uses both for added security.References
- AWS Documentation
- Amazon S3 FAQs
- Access Control List (ACL) Overview
- Managing ACLs in the AWS Management Console
- Editing Bucket Permissions
- AWS Command Line Interface (CLI) Documentation
- s3api
- list-buckets
- get-bucket-acl
- put-bucket-acl
- CloudFormation Documentation
- AccessControl
- Terraform Documentation
- AWS Provider
Unlock the Remediation Steps
Free 30-day Trial
Automatically audit your configurations with Conformity
and gain access to our cloud security platform.
![Confirmity Cloud Platform](/cloudoneconformity/assets/v2/images/common/conformity-platform-cloud.png)
You are auditing:
S3 Bucket Authenticated Users 'FULL_CONTROL' Access
Risk Level: Very High