Detections
Analytics

2.9 Ensure That the Log Metric Filter and Alerts Exist for VPC Network Changes

Information

It is recommended that a metric filter and alarm be established for Virtual Private Cloud (VPC) network changes.

Rationale:

It is possible to have more than one VPC within a project. In addition, it is also possible to create a peer connection between two VPCs enabling network traffic to route between VPCs.

Monitoring changes to a VPC will help ensure VPC traffic flow is not getting impacted.

Impact:

Enabling of logging may result in your project being charged for the additional logs usage. These charges could be significant depending on the size of the organization.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

From Google Cloud Console
Create the prescribed log metric:

Go to Logging/Logs-based Metrics by visiting https://console.cloud.google.com/logs/metrics and click 'CREATE METRIC'.

Click the down arrow symbol on Filter Bar at the rightmost corner and select Convert to Advanced Filter.

Clear any text and add:

resource.type='gce_network'
AND (protoPayload.methodName:'compute.networks.insert'
OR protoPayload.methodName:'compute.networks.patch'
OR protoPayload.methodName:'compute.networks.delete'
OR protoPayload.methodName:'compute.networks.removePeering'
OR protoPayload.methodName:'compute.networks.addPeering')

Click Submit Filter. Display logs appear based on the filter text entered by the user.

In the Metric Editor menu on the right, fill out the name field. Set Units to 1 (default) and Type to Counter. This ensures that the log metric counts the number of log entries matching the user's advanced logs query.

Click Create Metric.

Create the prescribed alert policy:

Identify the newly created metric under the section User-defined Metrics at https://console.cloud.google.com/logs/metrics.

Click the 3-dot icon in the rightmost column for the new metric and select Create alert from Metric. A new page appears.

Fill out the alert policy configuration and click Save. Choose the alerting threshold and configuration that makes sense for the user's organization. For example, a threshold of 0 for the most recent value will ensure that a notification is triggered for every owner change in the project:

Set 'Aggregator' to 'Count'

Set 'Configuration':

- Condition: above

- Threshold: 0

- For: most recent value

Configure the desired notification channels in the section Notifications.

Name the policy and click Save.

From Google Cloud CLI
Create the prescribed Log Metric:

Use the command: gcloud logging metrics create

Create the prescribed alert policy:

Use the command: gcloud alpha monitoring policies create

See Also

https://workbench.cisecurity.org/benchmarks/11843

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-2, 800-53|AU-3, 800-53|AU-3(1), 800-53|AU-7, 800-53|AU-12, CSCv7|6.2, CSCv7|6.3

Plugin: GCP

Control ID: 4849d95b508ebd573bb8c3fd118a7c3aa004f8f2db0853603c6beb18199a9aa4