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How the CVE Works:
The vulnerability in Gardener’s External DNS Management allows an attacker with administrative privileges in a Gardener project or shoot cluster to escalate privileges by injecting malicious Google service account credentials into a DNS secret. This occurs due to insufficient validation of DNS provider secrets, enabling unauthorized access to the seed cluster. The compromised credentials can then be used to manipulate DNS records or gain control over the seed cluster, impacting the entire shoot cluster management system.
DailyCVE Form:
Platform: Gardener External DNS Management
Version: <= v1.60.0
Vulnerability: Privilege Escalation
Severity: Critical
Date: May 19, 2025
What Undercode Say:
Exploitation:
1. Malicious Secret Injection:
apiVersion: v1 kind: Secret metadata: name: malicious-dns-secret type: Opaque data: serviceaccount.json: <base64-malicious-google-creds>
2. Exploit via kubectl:
kubectl apply -f malicious-secret.yaml -n shoot-namespace
3. Verify Compromise:
kubectl get dnsentries --all-namespaces
Mitigation:
1. Update Gardener:
helm upgrade gardener --version >=1.61.0
2. Restrict Secret Access:
kubectl create roleblock dns-secret-modifier --verb=create,update --resource=secrets
3. Audit Existing Secrets:
kubectl get secrets --field-selector type=Opaque -o json | jq '.items[] | select(.data.serviceaccount.json)'
Detection:
1. Log Analysis:
kubectl logs -l app=external-dns-management --since=24h | grep "unauthorized"
2. Network Policies:
apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: block-external-dns-exfiltration spec: podSelector: matchLabels: app: external-dns-management egress: - to: - namespaceSelector: matchLabels: role: seed-cluster
Remediation:
1. Rotate Compromised Credentials:
gcloud iam service-accounts keys rotate [email protected]
2. Revoke Unauthorized Access:
kubectl delete secret malicious-dns-secret -n shoot-namespace
References:
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
