Cis Azure Foundations 8.1.14

8.1.14 Ensure That 'Notify about alerts with the following severity' is Set to 'High' (Automated)

Description

Ensure that Microsoft Defender for Cloud is configured to send email notifications for alerts with a severity level of 'High' or above, ensuring that critical security threats are promptly communicated to the security team.

Rationale

Configuring alert notifications to trigger on 'High' severity ensures that the most critical security threats are escalated via email. High severity alerts typically indicate active threats, successful exploitation, or critical misconfigurations that require immediate attention. Without proper notification thresholds, security teams may miss critical alerts or be overwhelmed by lower-priority notifications.

Impact

Setting the notification threshold to 'High' will result in email notifications only for high-severity alerts. Medium and low severity alerts will still be visible in the Defender for Cloud portal but will not trigger email notifications. Organizations should ensure they have processes to review lower-severity alerts through the portal or other monitoring channels.

Audit Procedure

From Azure Portal:

1. Go to Microsoft Defender for Cloud.
2. Under Management, click Environment settings.
3. Click the name of a subscription.
4. Select the Email notifications blade.
5. Verify that Notify about alerts with the following severity (or higher) is set to High.

From Azure CLI:

az rest --method get --url "https://management.azure.com/subscriptions/{subscriptionId}/providers/Microsoft.Security/securityContacts?api-version=2020-01-01-preview"

Verify that alertNotifications.minimalSeverity is set to High.

From PowerShell:

Get-AzSecurityContact | Select-Object Name, AlertNotifications

Ensure AlertNotifications is enabled and the minimal severity is set to High.

Expected Result

The alert notification severity threshold should be set to High.

Remediation

From Azure Portal:

1. Go to Microsoft Defender for Cloud.
2. Under Management, click Environment settings.
3. Click the name of a subscription.
4. Select the Email notifications blade.
5. Set Notify about alerts with the following severity (or higher) to High.
6. Click Save.

From Azure CLI:

az rest --method put --url "https://management.azure.com/subscriptions/{subscriptionId}/providers/Microsoft.Security/securityContacts/default?api-version=2020-01-01-preview" --body '{"properties":{"alertNotifications":{"state":"On","minimalSeverity":"High"}}}'

From PowerShell:

Set-AzSecurityContact -Name "default" -AlertAdmin -NotifyOnAlert

Default Value

By default, email notifications for security alerts are not configured.

References

1. https://learn.microsoft.com/en-us/azure/defender-for-cloud/configure-email-notifications
2. https://learn.microsoft.com/en-us/rest/api/defenderforcloud/security-contacts
3. https://learn.microsoft.com/en-us/powershell/module/az.security/set-azsecuritycontact

Profile

• Level 1