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Event Information

  1. The v1.compute.backendBuckets.deleteSignedUrlKey event in GCP for Compute refers to the deletion of a signed URL key associated with a backend bucket.

  2. This event indicates that a specific signed URL key, which is used to grant temporary access to objects in a backend bucket, has been deleted.

  3. It is important to monitor this event as it can help track changes and ensure the security and access control of objects stored in backend buckets.

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Examples

  1. Unauthorized access: If security is impacted with v1.compute.backendBuckets.deleteSignedUrlKey in GCP for Compute, it could potentially allow unauthorized users to delete signed URL keys associated with backend buckets. This could lead to unauthorized access to the resources stored in the backend bucket, compromising the security of the data.

  2. Data loss: If security is impacted with v1.compute.backendBuckets.deleteSignedUrlKey in GCP for Compute, it could result in accidental deletion of signed URL keys. This could lead to a loss of access to the resources stored in the backend bucket, potentially causing data loss and disruption to the applications relying on those resources.

  3. Service disruption: If security is impacted with v1.compute.backendBuckets.deleteSignedUrlKey in GCP for Compute, it could be exploited to intentionally delete signed URL keys, causing a disruption in the availability of resources served by the backend bucket. This could result in service downtime and impact the overall performance and reliability of the applications relying on those resources.

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Remediation

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Using Console

  1. Enable VPC Flow Logs:
  • Go to the GCP Console and navigate to the VPC network where the Compute instances are located.
  • Select the subnet(s) associated with the instances.
  • Click on “Edit” and scroll down to the “Flow logs” section.
  • Enable flow logs by selecting the desired configuration (e.g., All metadata, Exclude private IP, etc.).
  • Choose the destination for the logs (e.g., Stackdriver Logging, Cloud Storage, Pub/Sub).
  • Click on “Save” to enable VPC Flow Logs for the selected subnet(s).
  1. Implement Network Security Groups:
  • Go to the GCP Console and navigate to the VPC network where the Compute instances are located.
  • Select the subnet(s) associated with the instances.
  • Click on “Edit” and scroll down to the “Firewall rules” section.
  • Create a new firewall rule by clicking on “Add firewall rule”.
  • Define the necessary parameters such as source IP ranges, protocols, and ports.
  • Apply the rule to the desired instances by selecting the appropriate target tags or target service accounts.
  • Click on “Save” to implement the network security group rule.
  1. Enable Cloud Security Scanner:
  • Go to the GCP Console and navigate to the Security Command Center.
  • Select the project where the Compute instances are located.
  • Click on “Enable” under the “Web Security Scanner” section.
  • Configure the scanner by providing the necessary details such as the starting URLs, authentication settings, and scanning options.
  • Click on “Start Scan” to initiate the scanning process.
  • Monitor the scan results and take appropriate actions to remediate any identified vulnerabilities or security issues.

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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 public IP for an instance:

    • Use the gcloud compute instances describe command to get the details of the instance.
    • Note down the instance name and zone.
    • Run the gcloud compute instances delete-access-config command to remove the public IP from the instance: 
      gcloud compute instances delete-access-config [INSTANCE_NAME] --zone [ZONE] --access-config-name "External NAT"

  2. Enable OS Login for an instance:

    • Use the gcloud compute instances describe command to get the details of the instance.
    • Note down the instance name and zone.
    • Run the gcloud compute instances add-metadata command to enable OS Login for the instance: 
      gcloud compute instances add-metadata [INSTANCE_NAME] --zone [ZONE] --metadata enable-oslogin=TRUE

  3. Restrict SSH access to specific IP ranges:

    • Use the gcloud compute firewall-rules list command to get the list of firewall rules.
    • Note down the name of the firewall rule that allows SSH access.
    • Run the gcloud compute firewall-rules update command to restrict SSH access to specific IP ranges: 
      gcloud compute firewall-rules update [FIREWALL_RULE_NAME] --source-ranges [IP_RANGE_1],[IP_RANGE_2],... --direction INGRESS

Please replace the placeholders ([INSTANCE_NAME], [ZONE], [FIREWALL_RULE_NAME], [IP_RANGE_1], [IP_RANGE_2], …) with the actual values specific to your 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 respond to security events:

    • Use the google-cloud-sdk library to interact with GCP Security Command Center API.
    • Write a Python script to retrieve security findings using the organizations().sources().findings().list() method.
    • Implement logic to filter and analyze the findings based on severity levels and specific event types.
    • Use the organizations().sources().findings().update() method to acknowledge or mitigate the security findings.

Please note that the provided code snippets are simplified examples, and you may need to modify them based on your specific requirements and the structure of your GCP environment.