CVE-2024-21626 (Leaky Vessels) → container escape

§ Context

Assumed environment: target runs runc < 1.1.12 (or BuildKit < 0.12.5). Attacker can push a custom image into the build / runtime pipeline.

§ Steps

1. 01
   Identify vulnerable runc versionReconnaissance

   W-RECON-FINGERPRINT— Tech Stack Fingerprinting
2. 02
   File descriptor points at host rootPrivilege Escalation

   K-PRIV-CONTAINER— Privileged Container Escape
3. 03
   Read/write host filesystemPrivilege Escalation

   K-HOSTPATH-MOUNT— hostPath Volume Mount
4. 04
   Craft image with WORKDIR /proc/self/fd/<N>Privilege Escalation

   K-CVE-2024-21626— runc CVE-2024-21626 (Leaky Vessels)
5. 05
   Trigger image build / runPersistence

   K-IMAGE-BACKDOOR— Backdoored Container Image

§ Frequently asked

What is the "CVE-2024-21626 (Leaky Vessels) → container escape" attack path?

Outdated runc lets a malicious image escape during 'docker build' or 'docker run' via a leaked file descriptor pointing at the host filesystem. It chains 5 steps drawn from real-world offensive-security techniques.

What starting position does this attack require?

The first step is Identify vulnerable runc version (W-RECON-FINGERPRINT) — a reconnaissance primitive. Assumed environment: target runs runc < 1.

What is the final impact of this kill-chain?

The final step lands on Trigger image build / run (K-IMAGE-BACKDOOR), which falls under Persistence. From here, an operator typically pivots into post-exploitation or maintains persistence.

How can defenders detect or prevent this attack?

Detection and prevention vary per step. Refer to each linked MITRE ATT&CK entry under "References" — every technique on that page lists defensive controls, detection telemetry, and known threat-actor usage.

§ Related dossiers

• Shared techniques2

  ArgoCD weak RBAC → cluster admin via custom Application

  ArgoCD installed with the default admin user and broad RBAC. Attacker creates an Application pointing at attacker manifests — ArgoCD syncs them with cluster-admin.

• Shared techniques2

  Privileged pod escape → cluster admin

  GenericWrite on a Deployment in the kube-system namespace lets you launch a privileged pod; the pod mounts the host filesystem and steals the kubeconfig of cluster-admin.

• Shared techniques2

  Docker socket exposed in pod → host root

  A workload mounts /var/run/docker.sock for convenience; spawn a container with the host root mounted, then chroot in for root on the node.