Dns.managedzones.update

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Event Information

1. The dns.managedZones.update event in GCP for CloudDNS indicates that a change has been made to a managed zone in Cloud DNS.
2. This event typically occurs when there is a modification to the DNS configuration, such as adding or removing DNS records, updating DNS settings, or changing zone properties.
3. It is important to monitor this event as it helps track changes made to the DNS infrastructure, ensuring that any modifications are intentional and in line with the desired DNS configuration.

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Examples

1. Unauthorized modification of DNS records: If security is impacted with dns.managedZones.update in GCP for CloudDNS, it could potentially allow unauthorized individuals to modify DNS records. This could lead to DNS hijacking or redirecting traffic to malicious websites, compromising the security and integrity of the domain.
2. Exposure of sensitive DNS information: A security impact of dns.managedZones.update in GCP for CloudDNS could result in the exposure of sensitive DNS information. If unauthorized individuals gain access to modify DNS zones, they may be able to view or extract sensitive information such as IP addresses, subdomains, or other DNS records, which could be used for further attacks or reconnaissance.
3. Disruption of DNS resolution: Another security impact of dns.managedZones.update in GCP for CloudDNS could be the disruption of DNS resolution. If unauthorized modifications are made to DNS zones, it could result in incorrect or inconsistent DNS resolution, leading to service disruptions, potential downtime, or even DNS cache poisoning attacks. This can impact the availability and reliability of services relying on DNS for name resolution.

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Remediation

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Using Console

1. Enable DNSSEC for GCP CloudDNS:
   • Go to the GCP Console and navigate to the Cloud DNS page.
   • Select the DNS zone for which you want to enable DNSSEC.
   • Click on the “DNSSEC” tab.
   • Click on the “Enable DNSSEC” button.
   • Follow the instructions provided to complete the DNSSEC setup process.
2. Implement DNS firewall rules for GCP CloudDNS:
   • Go to the GCP Console and navigate to the Cloud DNS page.
   • Select the DNS zone for which you want to implement DNS firewall rules.
   • Click on the “Firewall rules” tab.
   • Click on the “Create a rule” button.
   • Configure the necessary parameters such as source IP ranges, target IP ranges, and action.
   • Click on the “Create” button to create the DNS firewall rule.
3. Monitor DNS query logs for GCP CloudDNS:
   • Go to the GCP Console and navigate to the Cloud DNS page.
   • Select the DNS zone for which you want to monitor DNS query logs.
   • Click on the “Logs” tab.
   • Enable the “Query logs” toggle switch.
   • Configure the necessary parameters such as log retention period and log sink destination.
   • Click on the “Save” button to start monitoring DNS query logs.

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Using CLI

1. Ensure proper IAM permissions:
   • Grant the necessary IAM roles to the user or service account executing the CLI commands.
   • Use the gcloud projects add-iam-policy-binding command to add IAM roles to a project.
2. Implement DNSSEC for CloudDNS:
   • Enable DNSSEC for a managed zone using the gcloud dns managed-zones update command with the --dnssec-state flag set to on.
   • Sign the zone using the gcloud dns dns-keys sign-zone command.
3. Enable logging and monitoring for CloudDNS:
   • Enable query logging for a managed zone using the gcloud dns managed-zones update command with the --enable-query-logging flag set to true.
   • Create a log sink to export the logs to a desired destination using the gcloud logging sinks create command.
   • Enable monitoring and alerting for CloudDNS using the gcloud alpha monitoring policies create command to create a policy and gcloud alpha monitoring policies update command to update the policy.

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Using Python

1. Ensure DNSSEC is enabled:
   • Use the google-cloud-dns Python library to interact with the Cloud DNS API.
   • Use the dnssecConfig method to retrieve the current DNSSEC configuration for a specific managed zone.
   • If DNSSEC is not enabled, use the update method to enable DNSSEC for the managed zone.

from google.cloud import dns

def enable_dnssec(project_id, zone_name):
    client = dns.Client(project=project_id)
    zone = client.zone(zone_name)
    zone.fetch()
    
    if not zone.dnssec_config:
        zone.dnssec_config = dns.DnssecConfig(state=dns.DnssecState.ON)
        zone.update()
        print(f"DNSSEC enabled for zone: {zone_name}")
    else:
        print(f"DNSSEC is already enabled for zone: {zone_name}")

2. Implement DNS logging:
   • Use the logging Python library to interact with the Cloud Logging API.
   • Create a log sink to export DNS logs to a destination of your choice (e.g., BigQuery, Cloud Storage, Pub/Sub).
   • Configure the log sink to filter DNS-related logs based on specific criteria (e.g., log severity, resource type).
   • Enable the log sink to start exporting DNS logs.

from google.cloud import logging_v2

def create_dns_log_sink(project_id, sink_name, destination_uri, filter_expr):
    client = logging_v2.LoggingServiceV2Client()
    parent = client.project_path(project_id)
    
    sink = {
        "name": sink_name,
        "destination": destination_uri,
        "filter": filter_expr,
        "output_version_format": "V2",
    }
    
    response = client.create_sink(parent, sink)
    print(f"DNS log sink created: {response.name}")

3. Monitor DNS changes with Cloud Monitoring:
   • Use the google-cloud-monitoring Python library to interact with the Cloud Monitoring API.
   • Create a metric descriptor to define a custom metric for DNS changes.
   • Create a metric time series to record the DNS changes using the custom metric descriptor.
   • Set up an alerting policy to trigger notifications based on specific conditions (e.g., sudden increase in DNS changes).

from google.cloud import monitoring_v3

def create_dns_change_metric(project_id, metric_type, metric_kind, value_type):
    client = monitoring_v3.MetricServiceClient()
    project_name = client.project_path(project_id)
    
    descriptor = {
        "type": metric_type,
        "metric_kind": metric_kind,
        "value_type": value_type,
        "labels": [
            {
                "key": "zone",
                "value_type": "STRING",
                "description": "Managed zone name"
            }
        ]
    }
    
    response = client.create_metric_descriptor(project_name, descriptor)
    print(f"DNS change metric created: {response.name}")