SNS topic should not be accessible over the public internet
Description
Update your Amazon Simple Notification Service (SNS) topic permissions.
Rationale
Publicly-accessible topics allow unauthorized users access to receive and publish messages and subscribe to exposed topics.
From the console
Follow the Using identity-based policies with Amazon SNS docs to learn how to create or add to a policy in the AWS Console.
From the command line
If you do not have an access control policy, create one.
Select SNS Topic Policy as the type of policy.
Add a statement to allow only specific IAM users and roles to have access to the topic. For example:
Effect: `Allow`
Principal: `arn:aws:iam::123456789012:root`
Action: `Add permission`
Amazon Resource Name: `arn:aws:iam::123456789012:root`
If you do have an access control policy, follow the add-permissions docs to add a permission to your existing policy.
