CAS-004 Security Architecture Practice Question
A company is deploying containerized applications on Kubernetes and needs to ensure that only authorized images are run in the cluster. Which Kubernetes resource should be used to enforce policies on what containers can run, including image source restrictions?
⚠ Common exam trap
CAS-005 often tests the RBAC-vs-admission-control boundary; candidates pick RBAC because it 'controls access,' but RBAC governs who can act, not what images are allowed to run.
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
✓
Admission controllers
Admission controllers intercept requests to the Kubernetes API server before objects are persisted, and can validate or mutate them — including rejecting pods whose images come from unauthorized registries or lack required signatures. This is the correct enforcement point for cluster-wide policy on what containers may run.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Role-Based Access Control (RBAC)
Why it's wrong here
RBAC authorises API verbs for users and service accounts; it cannot inspect pod specifications, so image registry or digest restrictions are never evaluated. RBAC is correct when the requirement is limiting who may create, modify or delete workloads within a namespace.
- ✗
Network policies
Why it's wrong here
Network policies filter pod ingress and egress traffic at layers 3 and 4; they never parse container image references, so unauthorised registries still deploy. Network policies are correct when the requirement is segmenting pod-to-pod communication or blocking egress to specific CIDRs.
- ✗
Seccomp profiles
Why it's wrong here
Seccomp profiles restrict which Linux system calls a container process may invoke; they do not evaluate image provenance, so any registry's image still starts. Seccomp is correct when the requirement is reducing kernel attack surface by blocking syscalls such as ptrace or mount.
- ✓
Admission controllers
Why this is correct
Admission controllers intercept API server requests before persistence, so a ValidatingAdmissionWebhook can reject pods whose images fail source or signature checks. This enforces policy at creation time, which is exactly the image-authorisation constraint the stem requires.
Go deeper
Related to this question
About these practice questions
This CAS-005 question is part of Courseiva's 973-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 September 2026 · checked against the official CompTIA exam blueprint
This CAS-005 practice question is part of Courseiva's free CompTIA 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 CAS-005 exam.