- A
The container is missing a memory limit and gets OOMKilled
Why wrong: OOMKilled would show OOMKilled status, not necessarily CrashLoopBackOff.
- B
The namespace has a PodSecurity enforce level that restricts hostPID and hostNetwork
HostPID and hostNetwork are restricted in baseline and restricted levels, causing the pod to be rejected or crash.
- C
The 'hostPID' and 'hostNetwork' fields cannot be combined
Why wrong: They can be combined; no technical restriction.
- D
The pod lacks the necessary Linux capabilities
Why wrong: hostPID/hostNetwork do not require additional capabilities beyond what's default.
Question 136 of 997
hostPID and hostNetwork Pod Crash Due to PodSecurity Enforce
This CKS practice question tests your understanding of system hardening. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. A key principle to apply: podSecurity Standards. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
An administrator runs 'kubectl run test-pod --image=nginx --dry-run=client -o yaml > pod.yaml', then adds 'hostPID: true' and 'hostNetwork: true' to the pod's spec. After applying with 'kubectl apply -f pod.yaml', the pod is created but immediately goes into 'CrashLoopBackOff'. What is the likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"immediately / without restart"Why it matters: Time or reboot constraint — the correct answer must take effect right away without requiring a reboot or reload.
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
✓
The namespace has a PodSecurity enforce level that restricts hostPID and hostNetwork
The pod is created but enters CrashLoopBackOff because the namespace's PodSecurity enforce level (e.g., 'restricted') blocks the use of hostPID and hostNetwork. Although the pod passes admission (if the enforce level is set to warn or audit), the runtime security constraints prevent the container from starting correctly, leading to a crash. The nginx container may fail due to missing capabilities or inability to access host resources under the restricted profile.
Key principle: PodSecurity Standards
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The container is missing a memory limit and gets OOMKilled
Why it's wrong here
OOMKilled would show OOMKilled status, not necessarily CrashLoopBackOff.
- ✓
The namespace has a PodSecurity enforce level that restricts hostPID and hostNetwork
Why this is correct
HostPID and hostNetwork are restricted in baseline and restricted levels, causing the pod to be rejected or crash.
Clue confirmation
The clue word "immediately / without restart" in the question point toward this answer.
Related concept
PodSecurity Standards
- ✗
The 'hostPID' and 'hostNetwork' fields cannot be combined
Why it's wrong here
They can be combined; no technical restriction.
- ✗
The pod lacks the necessary Linux capabilities
Why it's wrong here
hostPID/hostNetwork do not require additional capabilities beyond what's default.
Common exam traps
Common exam trap: answer the scenario, not the keyword
A common misconception is that hostPID and hostNetwork cause instant runtime errors due to missing capabilities or incompatibility. In reality, the CrashLoopBackOff is triggered by PodSecurity enforcement: even if the pod is admitted (e.g., in warn mode), the restricted security context prevents the container from functioning, causing repeated failures.
Trap categories for this question
Command / output trap
OOMKilled would show OOMKilled status, not necessarily CrashLoopBackOff.
Detailed technical explanation
How to think about this question
PodSecurity admission evaluates pods against three levels (privileged, baseline, restricted) based on the namespace's labels (e.g., `pod-security.kubernetes.io/enforce=restricted`). When `hostPID` or `hostNetwork` is set to true, the pod violates the restricted level, which blocks these host namespace sharing features. The admission controller can either reject the pod at creation or, if the policy is set to `warn` or `audit`, allow creation but the pod may still fail at runtime if a mutating webhook or other security mechanism enforces the restriction, resulting in a CrashLoopBackOff.
KKey Concepts to Remember
- PodSecurity Standards
- hostPID
- hostNetwork
- CrashLoopBackOff
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
PodSecurity Standards
Real-world example
How this comes up in practice
A practitioner preparing for the CKS exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. PodSecurity Standards Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Review podSecurity Standards, then practise related CKS questions on the same topic to reinforce the concept.
- →
System Hardening — study guide chapter
Learn the concepts, then practise the questions
- →
System Hardening practice questions
Targeted practice on this topic area only
- →
All CKS questions
997 questions across all exam domains
- →
Certified Kubernetes Security Specialist CKS study guide
Full concept coverage aligned to exam objectives
- →
CKS practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related CKS practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Monitoring Logging and Runtime Security practice questions
Practise CKS questions linked to Monitoring Logging and Runtime Security.
Cluster Setup and Hardening practice questions
Practise CKS questions linked to Cluster Setup and Hardening.
System Hardening practice questions
Practise CKS questions linked to System Hardening.
Minimize Microservice Vulnerabilities practice questions
Practise CKS questions linked to Minimize Microservice Vulnerabilities.
Supply Chain Security practice questions
Practise CKS questions linked to Supply Chain Security.
Monitoring, Logging and Runtime Security practice questions
Practise CKS questions linked to Monitoring, Logging and Runtime Security.
Cluster Setup practice questions
Practise CKS questions linked to Cluster Setup.
Cluster Hardening practice questions
Practise CKS questions linked to Cluster Hardening.
CKS fundamentals practice questions
Practise CKS questions linked to CKS fundamentals.
CKS scenario practice questions
Practise CKS questions linked to CKS scenario.
CKS troubleshooting practice questions
Practise CKS questions linked to CKS troubleshooting.
Practice this exam
Start a free CKS practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this CKS question test?
System Hardening — This question tests System Hardening — PodSecurity Standards.
What is the correct answer to this question?
The correct answer is: The namespace has a PodSecurity enforce level that restricts hostPID and hostNetwork — The pod is created but enters CrashLoopBackOff because the namespace's PodSecurity enforce level (e.g., 'restricted') blocks the use of hostPID and hostNetwork. Although the pod passes admission (if the enforce level is set to warn or audit), the runtime security constraints prevent the container from starting correctly, leading to a crash. The nginx container may fail due to missing capabilities or inability to access host resources under the restricted profile.
What should I do if I get this CKS question wrong?
Review podSecurity Standards, then practise related CKS questions on the same topic to reinforce the concept.
Are there clue words in this question I should notice?
Yes — watch for: "immediately / without restart". Time or reboot constraint — the correct answer must take effect right away without requiring a reboot or reload.
What is the key concept behind this question?
PodSecurity Standards
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Keep practising
More CKS practice questions
- Which flag is used to restrict the kubelet's ability to modify node status and pods?
- A Falco rule has priority `WARNING` and output: `Sensitive file opened (user=%user.name command=%proc.cmdline file=%fd.n…
- Falco detects a shell being opened inside a container. Which Falco rule field is used to specify the syscall condition f…
- A security audit reveals that a ServiceAccount named 'monitor' has a ClusterRoleBinding to the cluster-admin role. What…
- Match each Kubernetes security component to its description.
- Match each Kubernetes certificate type to its usage.
Last reviewed: Jul 4, 2026
This CKS practice question is part of Courseiva's free CNCF 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 CKS exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.