KCSA: Kubernetes and Cloud Native Security AssociateDemo

Repudiation involves undermining accountability or auditability so that actions cannot be reliably traced to an actor. Disabling log forwarding suppresses evidence needed for incident response and attribution.

etcd is the Kubernetes cluster’s sensitive backing datastore. Direct access can read or alter cluster state and bypass Kubernetes API authorization, admission, and audit controls, so network access should be restricted to the Kubernetes API server. Kubernetes: API Server Bypass Risks

Automated security testing tools can incorrectly flag harmless behavior as vulnerabilities (false positives) or fail to identify real vulnerabilities (false negatives). Human expertise and validation remain necessary to interpret and investigate the results.

Kubernetes processes API requests by authenticating the requester, authorizing the requested operation, and then running admission controllers. Admission control can mutate or reject an authorized request before the API object is validated and stored.

The Center for Internet Security publishes CIS Kubernetes Benchmarks, including guidance for Kubernetes itself and managed Kubernetes offerings such as Amazon EKS, Azure AKS, Google GKE, and Oracle OKE.

A validating admission controller or admission webhook can check an image’s signatures and reject the Pod admission request when verification fails, preventing the unsigned image from running. Kubernetes documentation identifies image-signature and attestation validation as a use case for dynamic admission control.

A Kubernetes Secret volume passes confidential data to the Pod as read-only files and is backed by tmpfs, so it is not written to nonvolatile storage. ConfigMaps are intended for non-confidential configuration, and secrets should not be embedded in container images. Environment variables are supported, but a Secret volume is the preferred choice here.

kubectl sends requests to the Kubernetes API server. The API server processes the requested change to the Deployment before downstream control-plane components or node kubelets reconcile it.

A container breakout is an escape from container isolation that enables a process to access the host operating system and potentially its files, resources, or other containers. It is commonly enabled by a container-runtime or kernel vulnerability.

Pipeline attestation provides cryptographically verifiable evidence that a software artifact completed required trusted processes, enabling deployment policy to verify its provenance and integrity and reject artifacts that have been tampered with. Binary Authorization overview

For Kubernetes resource permissions, RBAC uses the verbs get, list, watch, create, update, patch, delete, and deletecollection. These correspond to authorized resource operations, including collection reads, watches, and collection deletion.

An image pull secret needs permission only to authenticate and pull image layers and manifests from the private repository. Read-only access follows least privilege and avoids granting permissions to modify repository contents or administer the registry.

Regular security audits and vulnerability assessments help identify and remediate vulnerabilities, insecure configurations, and other security risks in a production Kubernetes cluster.

Application Pods should not inherit node credentials because a compromised Pod could use the node’s permissions, expanding the scope of access available to an attacker. Kubernetes guidance recommends limiting cloud instance credentials and preventing Pod access to node-associated credential sources; least-privilege, workload-specific identities reduce this blast radius.

Kubernetes RBAC blocks privilege escalation by requiring a user who creates or updates a Role to already possess every permission included in that Role at the applicable scope. The alternative exception is explicit escalate permission on roles or clusterroles in the rbac.authorization.k8s.io API group; bind and RoleBinding permissions apply to binding roles, not modifying a Role.

Physical access to the host that runs etcd can allow an attacker to obtain its database files and extract stored Kubernetes resource data. Kubernetes stores plaintext resource representations in etcd by default unless encryption at rest is configured. etcd client access and API-server-to-etcd communication should be protected with TLS and client certificates, so IP spoofing or merely intercepting protected network traffic does not by itself grant data access.

Vulnerability triage evaluates detected findings to determine whether they are valid vulnerabilities, including identifying false positives and prioritizing genuine issues for remediation.

The Node authorizer is a special-purpose Kubernetes API server authorization mode for kubelet requests. It limits kubelet access based on the node identity and the pods scheduled to that node.

A service mesh can secure service-to-service communication with mutual TLS (mTLS), which encrypts traffic in transit and authenticates both workloads. This protects the confidentiality of tenant traffic from node-level network eavesdropping.

X.509 client certificates provide authenticated access to kubelet HTTPS endpoints. Configuring the kubelet with a trusted client CA lets it validate client certificates, preventing unauthenticated clients from using the endpoint.

Cloud metadata services may expose node-level cloud credentials. Restricting Pod access to the metadata API through network policies prevents unauthorized workloads from retrieving those credentials.

In the shared responsibility model, cloud providers secure the foundational infrastructure that operates the cloud, while customers remain responsible for protecting their applications and data.

Each Kubernetes node requires a container runtime to run Pods, and kubeadm must be installed so that kubeadm join can bootstrap the worker into the cluster. Worker nodes do not host the Kubernetes API server, and the API server does not require a TLS-exposed container-runtime socket on each node. Kubernetes documentation: Creating a cluster with kubeadm