Securing Containers: preventing pompromise and pontaining breaches

Security by design (Pre-Deployment)

Build hardened images:

  • Start with minimal base images (Alpine, Distroless)

  • Remove unnecessary tools (no shells, debug binaries)

  • Scan for vulnerabilities before deployment (Trivy, Grype)

Lock down configurations:

  • Run as non-root (USER nobody)

  • Drop unneeded kernel capabilities (–cap-drop=ALL)

  • Make filesystems read-only (–read-only)

Example:

docker run --read-only --cap-drop=ALL --user nobody my-safe-app

Runtime protection

Monitor for suspicious activity:

  • Detect unexpected processes (Falco, Tracee)

  • Block anomalous network connections (Cilium, Calico)

  • Limit resource usage to prevent crypto-mining (–memory=500m)

Enforce immutability:

  • No live debugging in production

  • Terminate and redeploy instead of patching

Tooling:

falco -r rules/container_abuse.yaml  # Alert on shell spawns in containers

Scan everything, always

Layers matter: Scan base images and application layers. Check for:

  • Known CVEs

  • Embedded secrets

  • Malicious packages

Automate checks:

  • Block deployments if critical issues found

  • Re-scan weekly (new vulnerabilities emerge constantly)

Example:

trivy image --severity CRITICAL my-app:latest

When prevention fails: containment

  1. Network segmentation:

    • Service meshes (Istio mTLS)

    • Network policies (block cross-pod traffic)

  2. Forensic readiness:

    • Preserve compromised containers for analysis

    • Audit trails of container lifecycle events

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Last update: 2025-06-07 06:04