Cis AWS Foundations 4.1

Ensure CloudTrail is enabled in all regions

Description

AWS CloudTrail is a web service that records AWS API calls for your account and delivers log files to you. The recorded information includes the identity of the API caller, the time of the API call, the source IP address of the API caller, the request parameters, and the response elements returned by the AWS service. CloudTrail provides a history of AWS API calls for an account, including API calls made via the Management Console, SDKs, command line tools, and higher-level AWS services (such as CloudFormation).

Rationale

The AWS API call history produced by CloudTrail enables security analysis, resource change tracking, and compliance auditing. Additionally,

• ensuring that a multi-region trail exists will help detect unexpected activity occurring in otherwise unused regions
• ensuring that a multi-region trail exists will ensure that Global Service Logging is enabled for a trail by default to capture recordings of events generated on AWS global services
• for a multi-region trail, ensuring that management events are configured for all types of Read/Writes ensures the recording of management operations that are performed on all resources in an AWS account

Impact

S3 lifecycle features can be used to manage the accumulation and management of logs over time. See the following AWS resource for more information on these features:

1. https://docs.aws.amazon.com/AmazonS3/latest/dev/object-lifecycle-mgmt.html

Audit Procedure

Using AWS Console

1. Sign in to the AWS Management Console and open the CloudTrail console at https://console.aws.amazon.com/cloudtrail
2. Click on Trails in the left navigation pane
3. You will be presented with a list of trails across all regions
4. Ensure that at least one Trail has Yes specified in the Multi-region trail column
5. Click on a trail via the link in the Name column
6. Ensure Logging is set to ON
7. Ensure Multi-region trail is set to Yes
8. In the section Management Events, ensure that API activity set to ALL

Using AWS CLI

1. List all trails:

aws cloudtrail describe-trails

2. Ensure IsMultiRegionTrail is set to true:

aws cloudtrail get-trail-status --name <trail-name>

3. Ensure IsLogging is set to true:

aws cloudtrail get-event-selectors --trail-name <trail-name>

4. Ensure there is at least one fieldSelector for a trail that equals Management:

• This should NOT output any results for Field: "readOnly". If either true or false is returned, one of the checkboxes (read or write) is not selected.

Example of correct output:

"TrailARN": "<your_trail_ARN>",
    "AdvancedEventSelectors": [
        {
            "Name": "Management events selector",
            "FieldSelectors": [
                {
                    "Field": "eventCategory",
                    "Equals": [
                        "Management"
                    ]
                }
            ]
        }
    ]

Expected Result

At least one multi-region trail exists with IsMultiRegionTrail set to true, IsLogging set to true, and management events configured for all read/write types.

Remediation

Using AWS Console

1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/cloudtrail.
2. Click on Trails in the left navigation pane.
3. Click Get Started Now if it is presented, then:
   • Click Add new trail.
   • Enter a trail name in the Trail name box.
     • A trail created in the console is a multi-region trail by default.
   • Specify an S3 bucket name in the S3 bucket box.
   • Specify the AWS KMS alias under the Log file SSE-KMS encryption section, or create a new key.
   • Click Next.
4. Ensure the Management events check box is selected.
5. Ensure both Read and Write are checked under API activity.
6. Click Next.
7. Review your trail settings and click Create trail.

Using AWS CLI

Create a multi-region trail:

aws cloudtrail create-trail --name <trail-name> --bucket-name <s3-bucket-for-cloudtrail> --is-multi-region-trail

Enable multi-region on an existing trail:

aws cloudtrail update-trail --name <trail-name> --is-multi-region-trail

Note: Creating a CloudTrail trail via the CLI without providing any overriding options configures all read and write Management Events to be logged by default.

Default Value

By default, CloudTrail is not enabled in any region.

References

1. CCE-78913-1
2. https://docs.aws.amazon.com/awscloudtrail/latest/userguide/cloudtrail-concepts.html#cloudtrail-concepts-management-events
3. https://docs.aws.amazon.com/awscloudtrail/latest/userguide/logging-management-and-data-events-with-cloudtrail.html?icmpid=docs_cloudtrail_console#logging-management-events
4. https://docs.aws.amazon.com/awscloudtrail/latest/userguide/cloudtrail-supported-services.html#cloud-trail-supported-services-data-events

CIS Controls

MITRE ATT&CK Mappings

Profile

Level 1 | Manual