​
Event Information

  • The v1.compute.healthChecks.insert event in GCP for Compute refers to the creation of a health check for a virtual machine instance.
  • This event indicates that a new health check has been added to monitor the health and availability of a specific VM instance.
  • Health checks are used to periodically send requests to the VM instance and verify its responsiveness, ensuring that it is functioning properly and able to handle incoming traffic.

​
Examples

  1. Unauthorized access: If security is impacted with v1.compute.healthChecks.insert in GCP for Compute, it could potentially allow unauthorized users to create or modify health checks. This could lead to the creation of malicious health checks that could be used to exploit vulnerabilities in the system or disrupt the normal functioning of the application.

  2. Data exposure: If security is impacted with v1.compute.healthChecks.insert in GCP for Compute, it could result in the exposure of sensitive information. For example, if an attacker gains access to the health check creation process, they may be able to extract or manipulate data that is being used to configure the health checks. This could include sensitive configuration details or even credentials used for authentication.

  3. Service disruption: If security is impacted with v1.compute.healthChecks.insert in GCP for Compute, it could lead to service disruption. An attacker could potentially create a large number of malicious health checks, overwhelming the system and causing it to become unresponsive or unavailable. This could result in downtime for the application and impact the availability and reliability of the services running on the Compute Engine instances.

​
Remediation

​
Using Console

To remediate the issues mentioned in the previous response for GCP Compute using the GCP console, you can follow these step-by-step instructions:

  1. Restricting SSH access:

    • Go to the GCP Console and navigate to the Compute Engine section.
    • Select the instance for which you want to restrict SSH access.
    • Click on the “Edit” button at the top of the page.
    • Scroll down to the “Firewalls” section and click on “Add firewall rule”.
    • Provide a name for the firewall rule and set the “Targets” to “All instances in the network”.
    • In the “Source IP ranges” field, enter the IP range from which you want to allow SSH access (e.g., your organization’s IP range).
    • Set the “Protocols and ports” to allow SSH (port 22) traffic.
    • Click on the “Create” button to save the firewall rule.

  2. Enabling VPC Flow Logs:

    • Go to the GCP Console and navigate to the VPC Network section.
    • Select the VPC network for which you want to enable flow logs.
    • Click on the “Edit” button at the top of the page.
    • Scroll down to the “Flow logs” section and click on “Add flow log”.
    • Provide a name for the flow log and select the desired configuration options (e.g., sampling rate, metadata inclusion).
    • Choose the desired destination for the flow logs (e.g., Stackdriver Logging, Cloud Storage).
    • Click on the “Create” button to enable flow logs for the VPC network.

  3. Implementing IAM best practices:

    • Go to the GCP Console and navigate to the IAM & Admin section.
    • Select the project for which you want to implement IAM best practices.
    • Click on the “IAM” tab to view the project’s IAM policies.
    • Review the existing IAM policies and identify any potential issues or misconfigurations.
    • Make necessary changes to the IAM policies to align with best practices (e.g., removing unnecessary roles, granting least privilege).
    • Regularly review and audit the IAM policies to ensure ongoing compliance with best practices.

​
Using CLI

To remediate the issues mentioned in the previous response for GCP Compute using GCP CLI, you can follow these steps:

  1. Disable SSH access for the default service account:

    • Use the following command to get the email address of the default service account: 
      gcloud iam service-accounts list --filter="displayName:Compute Engine default service account"
    • Once you have the email address, use the following command to remove the roles associated with SSH access: 
      gcloud projects remove-iam-policy-binding PROJECT_ID --member=serviceAccount:EMAIL_ADDRESS --role=roles/compute.osLogin

  2. Enable VPC Flow Logs for network monitoring:

    • Use the following command to enable VPC Flow Logs for a specific subnet: 
      gcloud compute networks subnets update SUBNET_NAME --region=REGION --enable-flow-logs

  3. Restrict public access to Cloud Storage buckets:

    • Use the following command to update the bucket ACL and remove all public access: 
      gsutil iam ch allUsers:legacyObjectReader gs://BUCKET_NAME

Note: Replace PROJECT_ID with your GCP project ID, EMAIL_ADDRESS with the email address of the default service account, SUBNET_NAME with the name of the subnet, REGION with the region where the subnet is located, and BUCKET_NAME with the name of the Cloud Storage bucket.

​
Using Python

To remediate the issues mentioned in the previous response for GCP Compute using Python, you can use the following approaches:

  1. Enforce secure OS configurations:

    • Use the google-cloud-sdk library to programmatically configure OS-level security settings.
    • Write a Python script that utilizes the googleapiclient library to interact with the GCP Compute API and update the instance configurations.
    • Example script: 
      from googleapiclient import discovery
from oauth2client.client import GoogleCredentials

credentials = GoogleCredentials.get_application_default()
compute = discovery.build('compute', 'v1', credentials=credentials)

project = 'your-project-id'
zone = 'your-zone'
instance = 'your-instance-name'

request = compute.instances().setMetadata(
    project=project,
    zone=zone,
    instance=instance,
    body={
        'items': [
            {
                'key': 'startup-script',
                'value': '#!/bin/bash\n\n# Your startup script here'
            }
        ]
    }
)
response = request.execute()

  2. Implement network security controls:

    • Use the google-cloud-sdk library to programmatically configure network security settings.
    • Write a Python script that utilizes the googleapiclient library to interact with the GCP Compute API and update the firewall rules.
    • Example script: 
      from googleapiclient import discovery
from oauth2client.client import GoogleCredentials

credentials = GoogleCredentials.get_application_default()
compute = discovery.build('compute', 'v1', credentials=credentials)

project = 'your-project-id'
firewall_rule = 'your-firewall-rule-name'

request = compute.firewalls().update(
    project=project,
    firewall=firewall_rule,
    body={
        'allowed': [
            {
                'IPProtocol': 'tcp',
                'ports': ['80', '443']
            }
        ]
    }
)
response = request.execute()

  3. Enable logging and monitoring:

    • Use the google-cloud-logging library to programmatically enable logging for GCP Compute instances.
    • Write a Python script that utilizes the googleapiclient library to interact with the GCP Compute API and enable monitoring for the instances.
    • Example script: 
      from googleapiclient import discovery
from oauth2client.client import GoogleCredentials

credentials = GoogleCredentials.get_application_default()
compute = discovery.build('compute', 'v1', credentials=credentials)

project = 'your-project-id'
zone = 'your-zone'
instance = 'your-instance-name'

request = compute.instances().update(
    project=project,
    zone=zone,
    instance=instance,
    body={
        'name': instance,
        'labels': {
            'monitoring-enabled': 'true'
        }
    }
)
response = request.execute()

Please note that the provided scripts are just examples and may need to be modified based on your specific requirements and configurations.