cis-aws-foundations-4-4

name	cis-aws-foundations-4.4
description	Ensure that server access logging is enabled on the CloudTrail S3 bucket
category	cis-logging
version	7.0.0
author	cyberstrike-official
tags	["cis","aws","logging","cloudtrail","s3","server-access-logging"]
cis_id	4.4
cis_benchmark	CIS AWS Foundations Benchmark v7.0.0
tech_stack	["aws"]
cwe_ids	[]
chains_with	["cis-aws-foundations-4.1","cis-aws-foundations-4.5"]
prerequisites	[]
severity_boost	{}

Ensure that server access logging is enabled on the CloudTrail S3 bucket

Description

Server access logging generates a log that contains access records for each request made to your S3 bucket. An access log record contains details about the request, such as the request type, the resources specified in the request worked, and the time and date the request was processed. It is recommended that server access logging be enabled on the CloudTrail S3 bucket.

Rationale

By enabling server access logging on target S3 buckets, it is possible to capture all events that may affect objects within any target bucket. Configuring the logs to be placed in a separate bucket allows access to log information that can be useful in security and incident response workflows. In some environments (e.g., AWS Control Tower), logs may be delivered to the same bucket with appropriate prefixes, which is also an acceptable configuration.

Impact

N/A

Audit Procedure

Using AWS Console

1. Go to the Amazon CloudTrail console at https://console.aws.amazon.com/cloudtrail/home.
2. In the API activity history pane on the left, click Trails.
3. In the Trails pane, note the bucket names in the S3 bucket column.
4. Sign in to the AWS Management Console and open the S3 console at https://console.aws.amazon.com/s3.
5. Under All Buckets click on a target S3 bucket.
6. Click on Properties in the top right of the console.
7. Scroll down to Server access logging.
8. Ensure Server access logging is Enabled.
9. Verify the Target bucket where logs are delivered.

Using AWS CLI

1. Get the name of the S3 bucket that CloudTrail is logging to:

aws cloudtrail describe-trails --query 'trailList[*].S3BucketName'

2. Ensure logging is enabled on the bucket:

aws s3api get-bucket-logging --bucket <s3-bucket-for-cloudtrail>

Ensure the command does not return an empty output.

Sample output for a bucket with logging enabled:

{
  "LoggingEnabled": {