This CKS practice question tests your understanding of cluster setup and hardening. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. 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 `kube-bench` and sees that the check 'Ensure that the --protect-kernel-defaults flag is set to true' has failed. Which component does this check apply to?
etcd
Why wrong: etcd does not have this flag.
API server
Why wrong: This flag is not for the API server.
Kubelet
The flag belongs to the kubelet to protect kernel defaults.
Controller manager
Why wrong: Controller manager does not have this flag.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Kubelet
The `--protect-kernel-defaults` flag is a kubelet-specific security option that ensures the kubelet does not modify kernel parameters that could weaken node security. When set to true, it enforces that the kubelet respects kernel defaults, preventing privilege escalation via sysctl overrides. This check is part of the CIS Benchmark for the kubelet component, not for etcd, the API server, or the controller manager.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
etcd
Why it's wrong here
etcd does not have this flag.
API server
Why it's wrong here
This flag is not for the API server.
Kubelet
Why this is correct
The flag belongs to the kubelet to protect kernel defaults.
Related concept
Read the scenario before looking for a memorised answer.
Controller manager
Why it's wrong here
Controller manager does not have this flag.
Common exam traps
The trap here is that candidates often associate kernel parameter protection with the kubelet's sysctl management, but mistakenly attribute it to the API server or controller manager, which handle authorization and scheduling, not node-level kernel interactions.
Detailed technical explanation
The `--protect-kernel-defaults` flag is a kubelet runtime flag that, when set to true, prevents the kubelet from modifying kernel parameters like `vm.overcommit_memory` or `kernel.shmmax` via the `--allowed-unsafe-sysctls` feature. In practice, if this flag is false, a malicious pod could request unsafe sysctls that degrade node stability, such as disabling memory overcommit protection. The CIS Kubernetes Benchmark (section 4.2.6) specifically requires this flag to be true for worker node hardening.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A junior network technician can log in to a core router but cannot reach the enable prompt or configuration mode. The AAA server is authenticating the login — but the authorisation policy only grants privilege level 1, not 15. Authentication (who you are) is working; authorisation (what you can do) is not.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Cluster Setup and Hardening — study guide chapter
Learn the concepts, then practise the questions
Cluster Setup and 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
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise CKS questions linked to Monitoring Logging and Runtime Security.
Practise CKS questions linked to Cluster Setup and Hardening.
Practise CKS questions linked to System Hardening.
Practise CKS questions linked to Minimize Microservice Vulnerabilities.
Practise CKS questions linked to Supply Chain Security.
Practise CKS questions linked to Monitoring, Logging and Runtime Security.
Practise CKS questions linked to Cluster Setup.
Practise CKS questions linked to Cluster Hardening.
Practise CKS questions linked to CKS fundamentals.
Practise CKS questions linked to CKS scenario.
Practise CKS questions linked to CKS troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Cluster Setup and Hardening — This question tests Cluster Setup and Hardening — Read the scenario before looking for a memorised answer..
The correct answer is: Kubelet — The `--protect-kernel-defaults` flag is a kubelet-specific security option that ensures the kubelet does not modify kernel parameters that could weaken node security. When set to true, it enforces that the kubelet respects kernel defaults, preventing privilege escalation via sysctl overrides. This check is part of the CIS Benchmark for the kubelet component, not for etcd, the API server, or the controller manager.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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 →
Last reviewed: Jun 24, 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.