Monitor GCP resources inside service perimeters

Learn how to grant authorization to Cortex XSIAM to scan within your GCP service perimeter.

A service perimeter can provide an additional layer of security for your GCP projects. It serves as a fortified boundary around your Google Cloud resources. While resources inside the perimeter can communicate freely, the perimeter is designed to prevent unauthorized communication to Google Cloud services beyond its confines.

To enable Cortex XSIAM to scan assets and resources within your GCP perimeter, you must authorize Cortex XSIAM's identities to access the perimeter from within GCP. If you have a perimeter set up in your GCP project and you have not authorized Cortex XSIAM's identities to scan the perimeter, you will receive the following error:

Request is prohibited by organization's policy. vpcServiceControlsUniqueIdentifier: {{<GCP-perimeter-ID>}}

Note: Each GCP cloud instance is assigned a scope within GCP. If the scope, whether it be organization, folder, or project, includes any projects with a service perimeter, this procedure must be performed for that cloud instance to authorize Cortex XSIAM to scan the resources in the perimeter.

Projects to include in the service perimeter

Enterprise GCP environments using VPC Service Controls must include all GCP projects that communicate with Cortex XSIAM in the service perimeter. Depending on your scan mode and enabled security capabilities, this includes more than one project.

Customer-owned projects

Include the following projects that you own:

Project	Description
Your monitored GCP project(s)	Every GCP project that Cortex XSIAM is configured to monitor. If your cloud instance scope is an organization or folder, this includes all projects within that scope.
Your outpost project	If you are using Scan with Outpost mode, include the dedicated GCP project where the Cortex Outpost infrastructure is deployed. You can find this project ID in the Cortex XSIAM Authorization Details dialog box.

Cortex XSIAM-owned projects

Include the following Cortex XSIAM-managed GCP projects. The exact project numbers for your tenant are listed in the Authorization Details dialog box in Cortex XSIAM (see Obtain Cortex XSIAM identity details below).

Project	Description	Scan mode
Cortex Platform project	The Cortex XSIAM platform project that hosts the cts-pod service account. This is the primary Cortex XSIAM identity that initiates all scanning operations.	Cloud Scan and Outpost Scan
Cortex Outpost project	The Cortex XSIAM-managed GCP project that hosts the scanning infrastructure (Compute Engine VMs, Pub/Sub, Cloud Storage).	Cloud Scan mode only

Identify the Cortex XSIAM-owned projects. Each Cortex XSIAM service account email contains the project it belongs to: the portion between @ and .iam.gserviceaccount.com. For example, a CTS service account of cts-pod@xdr-eu-<tenant-id>.iam.gserviceaccount.com identifies the Cortex Platform project as xdr-eu-<tenant-id>. All platform service accounts share this project, and all scanning service accounts share the Cortex Outpost project, identified the same way from the Cortex Engine service account email.

Service accounts to authorize

The service accounts that require authorization depend on your scan mode and the security capabilities you have enabled. All service account emails for your specific tenant are listed in the Authorization Details dialog box.

Platform service account (all configurations)

Service account	Format	Direction	Purpose
CTS service account	cts-pod@<cortex-platform-project>.iam.gserviceaccount.com	Ingress and Egress	Cortex XSIAM platform identity that impersonates the Cortex Engine service account to initiate scanning.

Outpost service accounts (Scan with Outpost mode)

If you are using Scan with Outpost mode, the following additional service accounts in the Outpost project must be authorized:

Service account	Format	Direction	Purpose
Cortex Engine	cortex-engine@<outpost-project>.iam.gserviceaccount.com	Egress	Unified service account for all Outpost operations. The CTS service account impersonates this identity.
Collector	collector-<project-number>@<outpost-project>.iam.gserviceaccount.com	Egress	Collects data from monitored GCP resources.
DSPM Scan Runner	dspm-scan-runner@<outpost-project>.iam.gserviceaccount.com	Egress	Runs Data Security Posture Management (DSPM) scanning instances. Required if DSPM is enabled.
Registry Scan Runner	registry-scan-runner@<outpost-project>.iam.gserviceaccount.com	Egress	Runs container registry scanning instances. Required if Registry Scanning is enabled.
Serverless Scanner	scanner-of-runner@<outpost-project>.iam.gserviceaccount.com	Egress	Runs serverless function scanning instances. Required if Serverless Scanning is enabled. Note: Serverless scanning is uncommon in environments using Google Cloud Run.

Audit log service account (if audit log collection is enabled)

Service account	Format	Direction	Purpose
Audit Logs Service Account	crtx-al-<suffix>@<your-project>.iam.gserviceaccount.com	Ingress	Subscribes to the Pub/Sub subscription to collect GCP audit logs.

Obtain Cortex XSIAM identity details

1. In your Cortex XSIAM tenant, select Settings → Data Sources & Integrations.

2. Hover over the Google Cloud Platform (GCP) row and select View Details.

3. In the Cloud Instances page, identify the GCP instance with the perimeter, right-click it and select Details.

4. In the details pane, click the more options icon and select Authorization Details.

5. The Authorization Details dialog box lists all service account emails and project numbers you need to add as approved identities in GCP.

Add Cortex XSIAM authorization values to GCP perimeter

1. Log into Google Cloud Platform Console.

2. Navigate to VPC Service Controls.

3. In the list of perimeters, select the perimeter to which you want to grant access to Cortex XSIAM.

4. In the Service perimeter details screen, click Edit.

5. In the Edit service perimeter screen, select Ingress policy.

6. In the Ingress rules pane, click Add an ingress rule.

7. Enter a Title for the ingress rule.

8. In the From section, under Identities, select Select identities & groups.

9. Click Add identities. In the Add identities pane, under Search identities, paste Cortex discovery role from Cortex XSIAM's Authorization Details dialog box. If there are more authorized values, paste each of them under Search identities. Click Add identities.

10. In the To section, under Resources, select Select projects.

11. Click Add projects. In the Add projects pane, select the relevant projects.

12. Under Operations or IAM roles, select All operations.

13. Click Next to add an egress rule.

14. In the Egress rules pane, click Add an egress rule.

15. Enter a Title for the egress rule.

16. In the From section, under Identities, select Select identities & groups.

17. Click Add identities. In the Add identities pane, under Search identities, paste Cortex discovery role from Cortex XSIAM's Authorization Details dialog box. If there are more authorized values, paste each of them under Search identities. Click Add identities.

18. In the To section, under Resources, select Select projects.

19. Click Add projects. In the Add projects pane, select the relevant projects.

20. Click Save. Confirm the changes and click Confirm.

Add Cortex-owned projects to the perimeter

To allow Cortex XSIAM's scanning infrastructure to communicate with your protected resources, you must also add the Cortex-owned projects to the perimeter as allowed resources:

1. In the Service perimeter details screen, click Edit.

2. Under Resources, click Add resources.

3. Add the Cortex XSIAM Platform project and, if applicable, the Cortex XSIAM Outpost project using the numeric project numbers from the Authorization Details dialog box.

4. Click Save and confirm.

The Cortex XSIAM authorization values have been added as approved identities in GCP.