Google CloudOverview
Cloud DNS logging records the queries from the name servers within your VPC to Stackdriver. Logged queries can come from Compute Engine VMs, GKE containers, or other GCP resources provisioned within the VPC.
Rationale
Security monitoring and forensics cannot depend solely on IP addresses from VPC flow logs, especially when considering the dynamic IP usage of cloud resources, HTTP virtual host routing, and other technology that can obscure the DNS name used by a client from the IP address.
Monitoring of Cloud DNS logs provides visibility to DNS names requested by the clients within the VPC. These logs can be monitored for anomalous domain names and evaluated against threat intelligence
Note: For full capture of DNS, firewall must block egress UDP/53 (DNS) and TCP/443 (DNS over HTTPS) to prevent client from using external DNS name server for resolution.
Impact
Enabling Cloud DNS logging might result in your project being charged for additional logs usage.
Remediation guidance
From Command Line
Add New DNS Policy With Logging Enabled
For each VPC network that needs a DNS policy with logging enabled:
gcloud dns policies create enable-dns-logging --enable-logging --description="Enable DNS Logging" --networks=VPC_NETWORK_NAME
The VPC_NETWORK_NAME can be one or more networks in comma-separated list
Enable Logging for Existing DNS Policy For each VPC network that has an existing DNS policy that needs logging enabled
gcloud dns policies update POLICY_NAME --enable-logging --networks=VPC_NETWORK_NAME
The VPC_NETWORK_NAME can be one or more networks in comma-separated list
Default Value
Cloud DNS logging is disabled by default on each network.
Google Cloud Console (Asset-Level)
- Open the affected project/resource from the finding details in Google Cloud Console.
- Navigate to the resource security/configuration settings.
- Apply the control-specific secure configuration.
- Save and re-run the check.
Service-wide remediation
Recommended when many resources are affected: fix the platform baseline first so new resources inherit the secure setting, then remediate the existing flagged resources in batches.
Google Cloud
Use organization or folder policies where available, shared project templates, logs and alerting baselines, and IaC modules so new resources inherit the secure setting.
Operational rollout
- Fix the baseline first at the account, subscription, project, cluster, or tenant scope that owns this control.
- Remediate the currently affected resources in batches, starting with internet-exposed and production assets.
- Re-scan and track approved exceptions with an owner and expiry date.
Query logic
These are the stored checks tied to this control.
Google Cloud VPCs without DNS logging
Connectors
Covered asset types
Expected check: eq []
{
vpcs(where: { dnsPolicy_NONE: { NOT: { enableLogging_IN: ["true"] } } }) {
...AssetFragment
}
}
