What is Kubernetes security?

Kubernetes security encompasses the practices, tools, and configurations used to protect Kubernetes clusters, workloads, and data. It includes authentication, authorization (RBAC), network policies, pod security standards, secrets management, and runtime security.

What is the CKS certification?

The Certified Kubernetes Security Specialist (CKS) is a CNCF certification that validates expertise in securing Kubernetes clusters. It covers cluster setup and hardening, system hardening, minimizing microservice vulnerabilities, and supply chain security.

What are Kubernetes network policies?

Network policies are Kubernetes resources that control pod-to-pod and pod-to-external traffic. They act as a firewall for your cluster, allowing you to specify which pods can communicate with each other based on labels, namespaces, and ports.

What are Pod Security Standards?

Pod Security Standards (PSS) are predefined security profiles that define different levels of pod security restrictions: Privileged (unrestricted), Baseline (minimally restrictive to prevent known privilege escalations), and Restricted (heavily restricted following security best practices).

What is RBAC in Kubernetes?

Role-Based Access Control (RBAC) is a Kubernetes authorization mechanism that regulates access to resources based on user roles. It uses Role, ClusterRole, RoleBinding, and ClusterRoleBinding resources to define and assign permissions to users and service accounts.

How do I secure etcd in Kubernetes?

Secure etcd by enabling encryption at rest for secrets, using TLS for client-server communication, restricting access to etcd endpoints via firewall rules, enabling authentication, and running regular backups. etcd stores all cluster data including secrets.

What is a container escape attack?

A container escape attack occurs when a process breaks out of container isolation to access the host system or other containers. Common vectors include privileged containers, hostPath mounts, and kernel exploits. Mitigate with Pod Security Standards and seccomp profiles.

What tools are used for Kubernetes security scanning?

Popular Kubernetes security tools include Trivy (vulnerability scanning), Falco (runtime security), kube-bench (CIS benchmarks), OPA Gatekeeper and Kyverno (policy enforcement), Kubescape (security posture), and Cosign (image signing).

CVE-2024-28248 — Cilium HTTP network policies bypassed intermittently

HIGH7.2CVE-2024-28248GHSA-68mj-9pjq-mc85

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Affected projects: cilium
Disclosed: March 18, 2024
Last updated: April 27, 2026

Affected versions

Project	Vulnerable range
Cilium	`>= 1.13.9, < 1.13.13`
Cilium	`>= 1.14.0, < 1.14.8`
Cilium	`>= 1.15.0, < 1.15.2`

Patched versions

Project	Fixed in
Cilium	`1.13.13`
Cilium	`1.14.8`
Cilium	`1.15.2`

References

Summary

Cilium's HTTP policies were not consistently applied to all traffic in the scope of the policies, leading to HTTP traffic being incorrectly and intermittently forwarded when it should have been dropped.

Impact

Any cluster relying on Cilium HTTP-layer enforcement to block requests — for example, restricting which HTTP paths or methods a workload may reach — could see those rules bypassed for some flows. The CVSS scope change indicates traffic that was supposed to be denied could traverse beyond the intended boundary. Operators using HTTP-aware policy as a primary security control should treat this as a defence-in-depth failure for the affected versions.

Detection

There is no specific log signature for the bypass; the failure is intermittent and policy-engine-internal. Operators on affected versions should assume HTTP-layer enforcement was incomplete and reason about the blast radius using L3/L4 policy and other controls. Compare HTTP request counts at the workload level (via Hubble or your service mesh) against expected policy outcomes — sustained anomalies for the affected period suggest exposure.

Mitigation

Upgrade to a patched version on the appropriate release line:

Cilium v1.15.2 or later (for the 1.15 line)
Cilium v1.14.8 or later (for the 1.14 line)
Cilium v1.13.13 or later (for the 1.13 line)

There is no workaround — affected users are strongly encouraged to upgrade.

Affected versions

Patched versions

References

Summary​

Impact​

Detection​

Mitigation​

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Summary

Impact

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