Control: 2.4 Ensure Log Metric Filter and Alerts Exist for Project Ownership Assignments/Changes

Description

In order to prevent unnecessary project ownership assignments to users/service-accounts and further misuses of projects and resources, all roles/Owner assignments should be monitored.

Members (users/Service-Accounts) with a role assignment to primitive role roles/Owner are project owners.

The project owner has all the privileges on the project the role belongs to. These are summarized below:

All viewer permissions on all GCP Services within the project
Permissions for actions that modify the state of all GCP services within the project
Manage roles and permissions for a project and all resources within the project
Set up billing for a project

Granting the owner role to a member (user/Service-Account) will allow that member to modify the Identity and Access Management (IAM) policy. Therefore, grant the owner role only if the member has a legitimate purpose to manage the IAM policy. This is because the project IAM policy contains sensitive access control data. Having a minimal set of users allowed to manage IAM policy will simplify any auditing that may be necessary.

Project ownership has the highest level of privileges on a project. To avoid misuse of project resources, the project ownership assignment/change actions mentioned above should be monitored and alerted to concerned recipients.

Sending project ownership invites
Acceptance/Rejection of project ownership invite by user
Adding role\Owner to a user/service-account
Removing a user/Service account from role\Owner

Remediation

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 the Filter Bar at the rightmost corner and select Convert to Advanced Filter.
Clear any text and add:

(protoPayload.serviceName="cloudresourcemanager.googleapis.com")
AND (ProjectOwnership OR projectOwnerInvitee)
OR (protoPayload.serviceData.policyDelta.bindingDeltas.action="REMOVE"
AND protoPayload.serviceData.policyDelta.bindingDeltas.role="roles/owner")
OR (protoPayload.serviceData.policyDelta.bindingDeltas.action="ADD"
AND protoPayload.serviceData.policyDelta.bindingDeltas.role="roles/owner")

Click Submit Filter. The logs display 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 the Type to Counter. This ensures that the log metric counts the number of log entries matching the advanced logs query.
Click Create Metric.

Create the display 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 desired metric and select Create alert from Metric. A new page opens.
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 zero(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 notifications channels in the section Notifications.
Name the policy and click Save.

From Google Cloud CLI

Create a 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 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

Usage

Run the control in your terminal:

powerpipe control run gcp_compliance.control.cis_v400_2_4

Snapshot and share results via Turbot Pipes:

powerpipe login
powerpipe control run gcp_compliance.control.cis_v400_2_4 --share

SQL

This control uses a named query:

with filter_data as (
  select
    m.project as project,
    display_name alert_name,
    count(m.name) metric_name
  from
    gcp_monitoring_alert_policy,
    jsonb_array_elements(conditions) as filter_condition
    join gcp_logging_metric m on m.filter ~ '\s*\(protoPayload.serviceName\s*=\s*"cloudresourcemanager.googleapis.com"\s*\)\s*AND\s*\(\s*ProjectOwnership\s*OR\s*projectOwnerInvitee\s*\)\s*OR\s*\(\s*protoPayload.serviceData.policyDelta.bindingDeltas.action\s*=\s*"REMOVE"\s*AND\s*protoPayload.serviceData.policyDelta.bindingDeltas.role\s*=\s*"roles/owner"\s*\)\s*OR\s*\(\s*protoPayload.serviceData.policyDelta.bindingDeltas.action\s*=\s*"ADD"\s*AND\s*protoPayload.serviceData.policyDelta.bindingDeltas.role\s*=\s*"roles/owner"\s*\)\s*'
    and filter_condition -> 'conditionThreshold' ->> 'filter' like '%metric.type="' || m.metric_descriptor_type || '"%'
  where
    enabled
  group by
    m.project, display_name, m.name
)
select
  'https://cloudresourcemanager.googleapis.com/v1/projects/' || project_id resource,
  case
    when d.metric_name > 0  then 'ok'
    else 'alarm'
  end as status,
  case
    when d.metric_name > 0
      then 'Log metric and alert exist for project ownership assignments/changes.'
    else 'Log metric and alert do not exist exist for project ownership assignments/changes.'
  end as reason
  
  , project_id as project
from
  gcp_project as p
  left join filter_data as d on d.project = p.name;