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Event Information

  1. The v1.compute.urlMaps.patch event in GCP for Compute refers to a modification or update made to a URL map configuration in the Google Cloud Platform.
  2. This event indicates that changes have been made to the settings of a URL map, which is used to route incoming requests to the appropriate backend service or target proxy based on the requested URL.
  3. The event can be triggered when modifications are made to the URL map’s path matcher rules, host rules, or any other relevant configuration settings. It is important to monitor and track these events to ensure the proper functioning and routing of traffic within your GCP environment.

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Examples

  1. Unauthorized access: If security is impacted with v1.compute.urlMaps.patch in GCP for Compute, it could potentially allow unauthorized access to sensitive resources. For example, if an attacker gains access to modify the URL mapping configuration, they could redirect traffic to a malicious website or gain access to restricted resources.
  2. Data exposure: Another security impact could be the exposure of sensitive data. If an unauthorized user modifies the URL mapping configuration, they could potentially redirect traffic to a different backend service that is not properly secured, leading to data leakage or unauthorized access to sensitive information.
  3. Denial of service: A security impact of v1.compute.urlMaps.patch in GCP for Compute could be a potential denial of service (DoS) attack. If an attacker modifies the URL mapping configuration to redirect a large amount of traffic to a specific backend service, it could overload the service and cause it to become unresponsive, resulting in a DoS situation for legitimate users.

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Remediation

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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 IAM roles and permissions.
    • Review the existing IAM roles and identify any unnecessary or overly permissive roles.
    • Remove any unnecessary roles and adjust the permissions of existing roles to follow the principle of least privilege.
    • Consider creating custom IAM roles with specific permissions tailored to the needs of different user groups.
    • Regularly review and audit the IAM roles and permissions to ensure they align with the organization’s security requirements.

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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
Please note that you need to replace the placeholders (PROJECT_ID, EMAIL_ADDRESS, SUBNET_NAME, REGION, and BUCKET_NAME) with the actual values specific to your GCP environment.

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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 interact with GCP Compute API.
    • Write a Python script to retrieve the list of instances in a project using the instances().list() method.
    • Iterate through the instances and check their OS configurations using the instances().get() method.
    • Implement checks for secure configurations such as disabling root SSH access, enforcing strong passwords, and enabling automatic security updates.
    • Use the instances().setMetadata() method to update the instance metadata with the desired configurations.
  2. Implement network security controls:
    • Use the google-cloud-sdk library to interact with GCP Compute API.
    • Write a Python script to retrieve the list of firewall rules in a project using the firewalls().list() method.
    • Iterate through the firewall rules and check for any insecure configurations such as allowing unrestricted access or using weak protocols.
    • Use the firewalls().update() method to modify the firewall rules and enforce secure configurations.
  3. Monitor and detect unauthorized access:
    • Use the google-cloud-sdk library to interact with GCP Compute API.
    • Write a Python script to retrieve the list of instances in a project using the instances().list() method.
    • Iterate through the instances and check their access logs using the instances().getSerialPortOutput() method.
    • Implement a monitoring mechanism to analyze the access logs and detect any unauthorized access attempts.
    • Use the logging().write() method to log any suspicious activities and take appropriate actions.
Please note that the provided code snippets are just high-level examples, and you may need to modify them based on your specific requirements and configurations.