Amazon Elastic File System (EFS) is a serverless file system that does not require provisioning or managing storage. Stored files can be automatically encrypted by the service. In the case that adversaries gain physical access to the storage medium or otherwise leak a message they are not able to access the data.

Ask Yourself Whether

There is a risk if you answered yes to any of those questions.

Recommended Secure Coding Practices

It’s recommended to encrypt EFS file systems that contain sensitive information. Encryption and decryption are handled transparently by EFS, so no further modifications to the application are necessary.

Sensitive Code Example

For aws_cdk.aws_efs.FileSystem

import { FileSystem } from 'aws-cdk-lib/aws-efs';

new FileSystem(this, 'unencrypted-explicit', {
    vpc: new Vpc(this, 'VPC'),
    encrypted: false // Sensitive
});

For aws_cdk.aws_efs.CfnFileSystem

import { CfnFileSystem } from 'aws-cdk-lib/aws-efs';

new CfnFileSystem(this, 'unencrypted-implicit-cfn', {
}); // Sensitive as encryption is disabled by default

Compliant Solution

For aws_cdk.aws_efs.FileSystem

import { FileSystem } from 'aws-cdk-lib/aws-efs';

new FileSystem(this, 'encrypted-explicit', {
    vpc: new Vpc(this, 'VPC'),
    encrypted: true
});

For aws_cdk.aws_efs.CfnFileSystem

import { CfnFileSystem } from 'aws-cdk-lib/aws-efs';

new CfnFileSystem(this, 'encrypted-explicit-cfn', {
    encrypted: true
});

See