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. 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.
Which TWO of the following are effective methods to harden the kubelet against unauthorized access?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Enable the NodeRestriction admission controller
Option C is correct because the NodeRestriction admission controller limits the Node and Pod objects a kubelet can modify, preventing a compromised node from escalating privileges or tampering with other workloads. This is a key Kubernetes-native control to harden the kubelet's authorization scope.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Set --read-only-port=10255
Why it's wrong here
This enables an insecure read-only port, which should be disabled (set to 0) for security.
✗
Enable --authentication-token-webhook
Why it's wrong here
Kubelet does not support webhook token authentication; it uses client certificates or static tokens.
✓
Enable the NodeRestriction admission controller
Why this is correct
NodeRestriction limits the kubelet's ability to modify node and pod objects, reducing the impact of a compromised kubelet.
Related concept
Read the scenario before looking for a memorised answer.
✓
Configure --client-ca-file and --tls-cert-file to require client certificates
Why this is correct
Client certificate authentication ensures only clients with valid certificates can access the kubelet.
Related concept
Read the scenario before looking for a memorised answer.
✗
Set --anonymous-auth=true
Why it's wrong here
This would allow unauthenticated access, weakening security.
Common exam traps
Common exam trap: answer the scenario, not the keyword
CNCF often tests the distinction between authentication (verifying identity) and authorization (limiting actions); candidates may confuse enabling authentication (Option B) with hardening authorization, but the question specifically asks for methods that harden against unauthorized access, which includes both authentication and authorization controls, and the correct answers (C and D) focus on authorization and mutual TLS authentication respectively.
Detailed technical explanation
How to think about this question
The NodeRestriction admission controller works by validating that a kubelet can only create/modify Node objects with a name matching its own node name and can only create/update Pod objects bound to its node. Under the hood, it uses the node's credentials (typically from a bootstrap token or client certificate) to enforce these constraints, preventing a compromised node from impersonating another node or modifying arbitrary pods. In a real-world scenario, without NodeRestriction, a malicious kubelet could delete pods on other nodes or alter node labels to disrupt scheduling.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
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
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CKS question in full detail.
System Hardening — This question tests System Hardening — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Enable the NodeRestriction admission controller — Option C is correct because the NodeRestriction admission controller limits the Node and Pod objects a kubelet can modify, preventing a compromised node from escalating privileges or tampering with other workloads. This is a key Kubernetes-native control to harden the kubelet's authorization scope.
What should I do if I get this CKS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
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 →
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.
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.