Container orchestration through Kubernetes has become the default deployment model for modern applications. Development teams package services into containers, define infrastructure as code, and deploy at a speed that would have seemed impossible a decade ago. Security has not kept pace with that velocity, and Kubernetes environments carry risks that traditional security tools were never designed to detect.
Misconfigured Kubernetes clusters expose dashboards to the internet, run containers with root privileges, and store secrets in plain text within configuration files. Each of these mistakes gives attackers a direct route into your application infrastructure without needing to exploit a single software vulnerability.
The Most Common Kubernetes Failures
Publicly accessible Kubernetes API servers top the list. The API server controls every aspect of the cluster, from deploying workloads to reading secrets. Exposing it to the internet without strong authentication is equivalent to publishing your admin password on your website. Automated scanners find exposed API servers within hours of deployment.
Excessive container privileges create the second major risk. Containers running as root with host filesystem access can escape their isolation entirely and compromise the underlying node. From there, an attacker can reach every other container on the same host and potentially pivot across the entire cluster through shared service account tokens and network policies that default to allow-all traffic.
Image supply chain security is frequently overlooked. Teams pull base images from public registries without verifying their integrity. A compromised base image propagates vulnerabilities or backdoors into every service built on top of it, affecting your entire application stack from a single poisoned dependency.
William Fieldhouse, Director of Aardwolf Security Ltd, comments: “Kubernetes gives development teams extraordinary power and flexibility. It also gives them extraordinary scope to make security mistakes at scale. A single misconfigured role binding can grant cluster-admin access to an entire namespace. We find these issues in nearly every Kubernetes assessment because the security model is complex and the documentation prioritises functionality over hardening.”
Securing Your Clusters
Enable RBAC and enforce least privilege for every service account and user. Implement network policies that deny traffic by default and permit only explicitly required flows between pods. Run containers as non-root with read-only filesystems wherever your application supports it. Scan container images for known vulnerabilities before they reach production.
Organisations hosting Kubernetes on AWS should include cluster security within their AWS penetration testing scope. Cloud-native attack paths that chain IAM role assumptions with Kubernetes service account tokens create privilege escalation routes that span both the cloud platform and the orchestration layer.
Complement manual testing with vulnerability scanning services that understand container environments. Traditional network scanners miss container-specific issues like exposed API endpoints, insecure pod security policies, and unrotated secrets. Use specialised tooling designed for the Kubernetes threat model.
Kubernetes security is not optional. If your applications run in containers, your security programme must extend into the orchestration layer. Ignoring it leaves a gap that attackers are increasingly skilled at exploiting.
