Disabling or deletion of Customer-Managed Keys should be monitored

Description

Real-time monitoring of API calls can be achieved by directing CloudTrail logs to CloudWatch logs and establishing corresponding metric filters and alarms. It is recommended to set up a metric filter and alarm for customer-created CMKs that change to a disabled or scheduled deletion state to ensure data accessibility.

Remediation

For instructions on setting up CloudWatch metric filters and alarms for CMK state changes, refer to the AWS CloudWatch Alarms for CloudTrail User Guide.

aws logs put-metric-filter --log-group-name <cloudtrail_log_group_name> \
--filter-name <disable_or_delete_cmk_changes_metric> --metric-transformations \
metricName=<disable_or_delete_cmk_changes_metric>,metricNamespace='CISBenchmark',metricValue=1 \
--filter-pattern '{($.eventSource = kms.amazonaws.com) && (($.eventName=DisableKey)||($.eventName=ScheduleKeyDeletion))}'

You can choose your own metricName and metricNamespace strings. Use the same metricNamespace for all Foundations Benchmark metrics to group them together.