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4.9 Ensure AWS Config configuration changes are monitored

Warning! Audit Deprecated

This audit has been deprecated and will be removed in a future update.

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Information

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs, or an external Security information and event management (SIEM) environment, and establishing corresponding metric filters and alarms.

It is recommended that a metric filter and alarm be established for detecting changes to AWS Config's configurations.

Rationale:

Monitoring changes to AWS Config configuration will help ensure sustained visibility of configuration items within the AWS account.

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail Logs can also be sent to an external Security information and event management (SIEM) environment for monitoring and alerting.

NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.

Solution

If you are using CloudTrails and CloudWatch, perform the following to setup the metric filter, alarm, SNS topic, and subscription:

Create a metric filter based on filter pattern provided which checks for AWS Configuration changes and the <cloudtrail_log_group_name> taken from audit step 1.

aws logs put-metric-filter --log-group-name <cloudtrail_log_group_name> --filter-name '<aws_config_changes_metric>' --metric-transformations metricName= '<aws_config_changes_metric>' ,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventSource = config.amazonaws.com) && (($.eventName=StopConfigurationRecorder)||($.eventName=DeleteDeliveryChannel)||($.eventName=PutDeliveryChannel)||($.eventName=PutConfigurationRecorder)) }'

Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together.

Create an SNS topic that the alarm will notify

aws sns create-topic --name <sns_topic_name>

Note: you can execute this command once and then re-use the same topic for all monitoring alarms.

Create an SNS subscription to topic created in step 2

aws sns subscribe --topic-arn <sns_topic_arn> --protocol <protocol_for_sns> --notification-endpoint <sns_subscription_endpoints>

Note: you can execute this command once and then re-use the SNS subscription for all monitoring alarms.

Create an alarm that is associated with the CloudWatch Logs Metric Filter created in step 1 and an SNS topic created in step 2

aws cloudwatch put-metric-alarm --alarm-name '<aws_config_changes_alarm>' --metric-name '<aws_config_changes_metric>' --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns_topic_arn>

See Also

https://workbench.cisecurity.org/benchmarks/14207

Item Details

References: CCE|CCE-79194-7, CSCv7|1.4, CSCv7|11.2, CSCv7|16.1

Plugin: amazon_aws

Control ID: ed0b4c32f63500573bdc7430ae17b0551715957eae8e5ccbaa2de6dd64ce45c7