KCSA Kubernetes Threat Model Practice Question
During a supply chain security audit, a platform engineer discovers that container images deployed into the cluster are being pulled from public registries without cryptographic verification of their provenance or integrity. Which integrated Kubernetes security control should be implemented alongside an admission webhook to verify image signatures before admission?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Policy-based admission control with Sigstore Cosign verification
Admission controllers like Kyverno or OPA Gatekeeper can integrate with tools like Cosign to enforce image signature verification prior to allowing a pod to be scheduled.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Kubelet TLS bootstrapping
Why it's wrong here
Kubelet TLS bootstrapping handles certificate issuance for worker node communication with the API server.
- ✗
Secret encryption at rest using a KMS provider
Why it's wrong here
Encryption at rest protects etcd contents, not the integrity or supply chain origin of container images.
- ✓
Policy-based admission control with Sigstore Cosign verification
Why this is correct
Correct. Validating admission policies or webhooks integrated with Cosign verify container image signatures and provenance at deploy time.
- ✗
ImagePolicyWebhook
Why it's wrong here
ImagePolicyWebhook is deprecated and traditionally only checked external endpoints based on image strings, whereas modern signature verification relies on cryptographic validation admission webhooks.
About these practice questions
This KCSA question is part of Courseiva's 320-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official CNCF / Linux Foundation exam blueprint
This KCSA practice question is part of Courseiva's free CNCF / Linux Foundation certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the KCSA exam.