Kubernetes has become the dominant platform for container orchestration, powering everything from startup applications to enterprise workloads at massive scale. Its flexibility and automation capabilities are remarkable, but they come with a security surface that demands dedicated attention. Misconfigured Kubernetes clusters have become a frequent target for attackers seeking access to cloud environments and the sensitive data they contain.

Default Kubernetes configurations prioritise ease of deployment over security hardening. Fresh installations often include overly permissive network policies, unauthenticated API server access, and default service accounts with unnecessary privileges. Teams that deploy clusters without reviewing and tightening these defaults create environments that attackers can compromise with well-known techniques.

Role-based access control in Kubernetes requires careful planning and ongoing management. Overly broad roles that grant cluster-wide permissions, service accounts with elevated privileges attached to application pods, and stale role bindings from former team members all create escalation opportunities. RBAC policies should follow least privilege principles, granting only the specific permissions each workload and user requires.

Container image security deserves attention at every stage of the pipeline. Base images from public registries frequently contain known vulnerabilities. Dependencies pulled during build processes may introduce compromised libraries. Without image scanning integrated into continuous integration pipelines, vulnerable containers reach production environments undetected.

Network policies in Kubernetes control communication between pods, namespaces, and external endpoints. Without explicit network policies, all pods can communicate with all other pods by default, which allows an attacker who compromises a single container to reach every other workload in the cluster. Implementing restrictive network policies limits lateral movement and contains breaches within smaller blast zones.

Expert Commentary

William Fieldhouse | Director of Aardwolf Security Ltd

“Kubernetes has transformed application deployment, but its complexity creates a security surface that many teams struggle to manage. Default configurations favour functionality over security, RBAC policies grow unwieldy, and container images often contain known vulnerabilities. Treating Kubernetes security as someone else’s problem is a recipe for compromise.”

Conducting AWS penetration testing that includes your Kubernetes infrastructure examines the full attack surface of your containerised workloads. Testers probe the cluster API, evaluate network segmentation, test RBAC configurations, and attempt to escape container boundaries to reach the underlying node infrastructure.

Secrets management in Kubernetes environments requires solutions beyond the default etcd storage. Kubernetes secrets stored without encryption at rest are accessible to anyone with API access. External secrets management tools that integrate with Kubernetes provide encryption, access auditing, and rotation capabilities that the native implementation lacks.

Runtime security monitoring detects anomalous behaviour within running containers. Processes that should not be executing, network connections to unexpected destinations, and file system modifications outside expected patterns all indicate potential compromise. Runtime tools provide visibility into container behaviour that static security measures cannot offer.

Regular web application penetration testing covers the applications running within your Kubernetes environment. Container security and application security are distinct disciplines that must work together. A perfectly hardened cluster hosting a vulnerable application still results in a breach. Testing both layers ensures comprehensive protection.

Kubernetes security requires specialised knowledge that traditional infrastructure teams may not possess. Investing in training, engaging specialists, and conducting regular security assessments specific to container orchestration platforms builds the capabilities needed to operate Kubernetes safely. The platform’s benefits are substantial, but only organisations that secure it properly can realise them without unacceptable risk.