The Danger of Default Kubernetes Networking

In a standard Kubernetes cluster, any pod can connect to any other pod across namespaces. If an attacker breaches a single public-facing web container, they can query internal databases, metadata endpoints, and internal microservices.

Implementing eBPF Network Policies with Cilium:

  • Eliminate slow iptables rules in favor of kernel-level eBPF packet inspection.
  • Enforce strict default-deny network policies where services can only communicate over explicitly whitelisted ports and protocols.
  • Terminate mutual TLS (mTLS) with cryptographically verifiable SPIFFE/SPIRE service identities.