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

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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.

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

Solution

From 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 Command Line:
Create the prescribed Log Metric:

Use the command: gcloud beta logging metrics create

Reference for command usage: https://cloud.google.com/sdk/gcloud/reference/beta/logging/metrics/create

Create the prescribed alert policy:

Use the command: gcloud alpha monitoring policies create

Reference for command usage: https://cloud.google.com/sdk/gcloud/reference/alpha/monitoring/policies/create

See Also

https://workbench.cisecurity.org/files/3817

Item Details

References: CSCv7|6.2, CSCv7|6.3

Plugin: GCP

Control ID: 520e7d8c597a57c52c7b716d5fc6abc1dca91fe971172534b30504d0c4297e6f