lacework-global-253
2.10 Ensure That the Log Metric Filter and Alerts Exist for Cloud Storage IAM Permission Changes (Automated)
Profile Applicability
• Level 1
Description
It is recommended that a metric filter and alarm be established for Cloud Storage Bucket IAM changes.
Rationale
Monitoring changes to cloud storage bucket permissions may reduce the time needed to detect and correct permissions on sensitive cloud storage buckets and objects inside the bucket.
Impact
Enabling of logging may result in your project being charged for the additional logs usage.
Audit
From Console:
Ensure the prescribed log metric is present:
For each project that contains cloud storage buckets, go to
Logging/Logs-based Metrics
by visiting https://console.cloud.google.com/logs/metrics.In the
User-defined Metrics
section, ensure at least one metric<Log_Metric_Name>
is present with the filter text:
resource.type=gcs_bucket
AND protoPayload.methodName="storage.setIamPermissions"
Ensure that the prescribed alerting policy is present:
Go to
Alerting
by visiting https://console.cloud.google.com/monitoring/alerting.Under the
Policies
section, ensure that at least one alert policy exists for the log metric above. Clicking on the policy should show that it is configured with a condition. For example,Violates when: Any logging.googleapis.com/user/<Log Metric Name> stream
is above a threshold of 0 for greater than 0 seconds
means that the alert will trigger for any new owner change. Verify that the chosen alerting thresholds make sense for the user's organization.Ensure that the appropriate notifications channels have been set up.
From Command Line:
Ensure that the prescribed log metric is present:
- List the log metrics:
gcloud beta logging metrics list --format json
- Ensure that the output contains at least one metric with the filter set to:
resource.type=gcs_bucket
AND protoPayload.methodName="storage.setIamPermissions"
- Note the value of the property
metricDescriptor.type
for the identified metric, in the formatlogging.googleapis.com/user/<Log Metric Name>
.
Ensure the prescribed alerting policy is present:
- List the alerting policies:
gcloud alpha monitoring policies list --format json
- Ensure that the output contains an least one alert policy where:
conditions.conditionThreshold.filter
is set tometric.type=\"logging.googleapis.com/user/<Log Metric Name>\"
- AND
enabled
is set totrue
Remediation
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 the
Filter Bar
at the rightmost corner and selectConvert to Advanced Filter
.Clear any text and add:
resource.type=gcs_bucket
AND protoPayload.methodName="storage.setIamPermissions"
Click
Submit Filter
. Display logs appear based on the filter text entered by the user.In the
Metric Editor
menu on right, fill out the name field. SetUnits
to1
(default) andType
toCounter
. 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 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 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
References
https://cloud.google.com/logging/docs/logs-based-metrics/
https://cloud.google.com/monitoring/custom-metrics/
https://cloud.google.com/monitoring/alerts/
https://cloud.google.com/logging/docs/reference/tools/gcloud-logging
https://cloud.google.com/storage/docs/overview
https://cloud.google.com/storage/docs/access-control/iam-roles