CRE-2025-0071

CoreDNS unavailableHigh

Impact: 9/10

Mitigation: 8/10

CRE-2025-0071View on GitHub

KubernetesNetworkingDNSHigh Availability

Description

CoreDNS deployment is unavailable or has no ready endpoints, indicating an imminent cluster-wide DNS outage.

Mitigation

**Immediate Actions:** - Check CoreDNS deployment status: `kubectl -n kube-system get deployment coredns` - Verify CoreDNS pod health: `kubectl -n kube-system get pods -l k8s-app=kube-dns` - Check CoreDNS logs: `kubectl -n kube-system logs -l k8s-app=kube-dns` **Common Fixes:** - Scale deployment if replicas are 0: `kubectl -n kube-system scale deploy/coredns --replicas=2` - Restart pods if configuration issues: `kubectl -n kube-system rollout restart deployment/coredns` - Verify kube-dns service endpoints: `kubectl -n kube-system get endpoints kube-dns`

References

• https://kubernetes.io/docs/tasks/administer-cluster/dns-debugging-resolution/
• https://coredns.io/manual/toc/#troubleshooting