cloud professional services

Jun 23, 2020 2:48:25 PM by Kirill Morozov

AWS S3 - How to Secure Your Storage


Amazon S3 is one of the largest cloud storage solutions. Over the past few years, there have been countless security breaches on this platform, most of them stemming from S3 security setting misconfigurations.

Let's explore some of the S3 storage security challenges, their solutions, and best practices.

S3 Security Challenges


This is an older access control mechanism on AWS S3. It has limited flexibility when it comes to usability. The XML document sets up the first layer of access. Even though only the owner has access, the account can be opened up to the public.

Bucket Policies

Bucket policy is the latest access control mechanism after ACLs. It uses a JSON format that makes it a bit more reliable than ACLs. There is the AWS Policy Generator that simplifies configuration with Bucket Policies. Nonetheless, ACLs are on the first tab, and it's easier to make something public than it is to change and review permissions on Bucket Policies.

IAM Policies

These are the permissions that you use to govern access throughout your AWS account. These permissions only apply to AWS users, so you cannot make your buckets public with them. Nonetheless, the service will expose your content when you allow access to another AWS service account.

Object ACLs and Policy Statements

These object-level controls use XML just like bucket ACL. These controls can grant access to anyone in any corner of the world with an AWS S3 account. There is a further risk of data leak with your policy statements. Both your Bucket and IAM Policy statements can override the object ACL and open up your buckets to the public.

Pre-Signed URLs

These are short-lived object-level policies used to share files. They are created using code, and anyone with the URL will have open access to your data.

How to protect data stored in AWS S3 buckets

Amazon Simple Storage Service (AWS S3) is among the oldest cloud services by AWS. Started in 2006, the service’s flexibility in storage sizes has made it popular among businesses regardless of the security challenges. The AWS 3 security model may be partially to blame for the cloud storage security challenges, but a large number of the breaches happen because users misunderstand the configurations.

Here are some possible solutions:

Use Amazon S3 block public access.

You can set up unified controls that limit access to your S3 resources. When you use Amazon S3 block access, the security controls are enforced regardless of how your resources are set up.

Use multi-factor authentication (MFA)

MFA works reliably well. Enforce MFA on your AWS Identity, Root user, and IAM users. You can similarly use MFA at your federate identity provider. That helps you to utilize the same MFA processes that currently exist in your organization.

Enforce least privilege policies

Control who gets permission to each of your AWS 3 resources. Set up actions that you want to allow and restrict. That will ensure that people only get the permission they need to perform a task.

Use IAM roles for applications

Do not store AWS credentials in the application. Instead, work with IAM roles to manage the temporary credentials for apps that need to access AWS S3. Do not distribute passwords to AWS service or Amazon EC2 instance.

Security Best Practices for AWS S3

S3 is not necessarily an insecure storage solution. The security and reliability of your resources depend on how well you secure, access, and use your data. Use these S3 best practices to enhance your AWS services security:

  • Protect data at rest and on transit with encryption
  • Configure life policy to move unwanted data and secure it
  • Identify and audit your S3 buckets
  • Identify and audit the encryption status of all your Amazon S3 buckets with Amazon S3 inventory
  • Use AWS S3 security monitoring solutions and metrics to maintain the security and reliability of your Amazon S3 resources.
  • Use Cloud Trail to log and maintain each event across AWS services.

Whether you are facing security, compliance, or performance challenges on AWS or any other cloud service, Cloudride has got your back. We provide comprehensive consultancy and implementation cloud solution services and have handled dozens of cloud migrations and optimization initiatives for businesses across all industries. We can help you optimize and maximize your business value from the cloud with assured security, compliance, and best practices.

Contact us to learn more.



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