Profile Applicability:
Level 2
Description:
AWS CloudTrail enables real-time monitoring of API calls by logging events to CloudWatch Logs or an external SIEM. Monitoring AWS Config changes ensures that AWS Config remains active and properly configured. AWS Config is a service that enables continuous monitoring of AWS resource configurations. Any unauthorized or accidental modifications to AWS Config can result in:
Loss of configuration history for compliance and security auditing.
Disruption in change tracking across AWS resources.
Security risks due to disabled configuration monitoring.
This control ensures that AWS Config configuration modifications (e.g., stopping, deleting, or modifying configuration recorders or delivery channels) are logged, monitored, and alerted using CloudWatch Alarms and Amazon SNS notifications.
Rationale:
Monitoring AWS Config changes helps detect:
Unauthorized modifications that disable AWS Config tracking.
Accidental misconfigurations that disrupt AWS resource compliance monitoring.
Security incidents involving unexpected configuration setting changes.
Impact:
Failure to monitor AWS Config changes can result in:
Lack of visibility into AWS resource configurations.
Failure to comply with security and compliance policies.
Inability to track changes for troubleshooting security incidents.
Enabling monitoring does not impact performance, but it requires AWS CloudTrail and CloudWatch costs.
Default Value:
AWS CloudTrail does not log AWS Config changes by default.
CloudWatch Alarms and SNS notifications must be manually configured to monitor AWS Config modifications.
Pre-Requisites:
AWS CloudTrail enabled with multi-region logging.
AWS CloudWatch Logs enabled and linked to CloudTrail.
IAM Permissions Required:
cloudtrail:DescribeTrails
cloudtrail:GetEventSelectors
logs:DescribeMetricFilters
cloudwatch:DescribeAlarms
sns:ListSubscriptionsByTopic
logs:PutMetricFilter, cloudwatch:PutMetricAlarm, sns:CreateTopic
Remediation
Test Plan:
Using AWS Console
Login to the AWS Management Console.
Navigate to CloudTrail: AWS CloudTrail Console
.Verify there is at least one multi-region CloudTrail trail enabled.
Ensure CloudTrail is logging management events:
Click on the trail and check Event Selectors.
Ensure management events are set to "All".
Check that CloudTrail logs are being sent to CloudWatch.
Navigate to CloudWatch Logs: AWS CloudWatch Console.
Ensure that a metric filter is created for AWS Config changes.
Check CloudWatch Alarms for alerts on AWS Config modifications.
Implementation Steps:
Using AWS CLI
Step 1: Create a Metric Filter for AWS Config Changes
aws logs put-metric-filter --log-group-name <trail-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)) }'Step 2: Create an SNS Topic for Notifications
aws sns create-topic --name aws-config-changes-alerts
Step 3: Subscribe to SNS Topic
aws sns subscribe --topic-arn <sns-topic-arn> --protocol email --notification-endpoint <your-email@example.com>
Step 4: Create a CloudWatch Alarm for AWS Config Changes
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>
Backout Plan:
Delete CloudWatch Alarm:
aws cloudwatch delete-alarms --alarm-names aws-config-changes-alarm
Remove the metric filter:
aws logs delete-metric-filter --log-group-name <trail-log-group-name> --filter-name aws-config-changes-metric
Delete SNS topic:
aws sns delete-topic --topic-arn <sns-topic-arn>