How to Find AWS CloudTrail Trails Missing Alarms for Unauthorized API Calls
Monitoring unauthorized API calls will help reveal application errors and may reduce time to detect malicious activity.
info
This security check is part of the CIS Amazon Web Services Benchmarks and is rated severity medium.
Prerequisites
This guide assumes that you have already installed and configured Fix Inventory to collect your AWS resources.
Directions
-
Execute the following
search
command in Fix Inventory Shell:> search is(aws_cloud_trail) and trail_is_multi_region_trail=true and trail_status.is_logging=true with(empty, --> is(aws_cloudwatch_log_group) with(any, --> is(aws_cloudwatch_metric_filter) and filter_pattern~"\$\.errorCode\s*=\s*\"\*UnauthorizedOperation\".+\$\.errorCode\s*=\s*\"AccessDenied\*\".+\$\.sourceIPAddress\s*!=\s*\"delivery.logs.amazonaws.com\".+\$\.eventName\s*!=\s*\"HeadBucket\""))
kind=aws_cloud_trail, ..., region=fixinventory-poweruser
kind=aws_cloud_trail, ..., account=poweruser-team -
Pipe the
search
command into thedump
command:> search is(aws_cloud_trail) and trail_is_multi_region_trail=true and trail_status.is_logging=true with(empty, --> is(aws_cloudwatch_log_group) with(any, --> is(aws_cloudwatch_metric_filter) and filter_pattern~"\$\.errorCode\s*=\s*\"\*UnauthorizedOperation\".+\$\.errorCode\s*=\s*\"AccessDenied\*\".+\$\.sourceIPAddress\s*!=\s*\"delivery.logs.amazonaws.com\".+\$\.eventName\s*!=\s*\"HeadBucket\"")) | dump
reported:
id: /aws/cloudtrail/123
name: some-name
ctime: '2022-12-05T22:53:14Z'
kind: aws_cloud_trail
age: 2mo28dThe command output will list the details of all non-compliant
aws_cloud_trail
resources.
Remediation
- It is recommended that a metric filter and alarm be established for unauthorized requests.
note
Please refer to the AWS CloudTrail documentation for details.