CAS-004 Security Architecture Practice Question
An organization is hardening its Kubernetes cluster. Which THREE of the following are effective controls to limit the blast radius of a compromised container?
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
✓
Implementing Kubernetes network policies to restrict pod-to-pod communication
Network policies restrict communication between pods, limiting lateral movement. Seccomp profiles restrict system calls, reducing attack surface. Pod Security Standards (PSS) enforce security contexts like not running as root. RBAC controls user access, not container-to-container. Image scanning identifies vulnerabilities but does not limit blast radius.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Using RBAC to restrict service account permissions
Why it's wrong here
RBAC controls what actions service accounts can perform, but does not directly limit the blast radius of a compromised container.
- ✓
Implementing Kubernetes network policies to restrict pod-to-pod communication
Why this is correct
Network policies limit which pods can communicate, containing potential lateral movement.
- ✗
Performing regular container image scanning for vulnerabilities
Why it's wrong here
Image scanning identifies vulnerabilities but does not limit the blast radius once a container is compromised.
- ✓
Applying seccomp profiles to limit system call availability
Why this is correct
Seccomp restricts the system calls a container can make, reducing the attack surface.
- ✓
Enforcing Pod Security Standards (PSS) such as 'restricted' policy
Why this is correct
PSS can prevent containers from running with elevated privileges, reducing impact of compromise.
Quick reference
AAA Protocol Comparison
| Protocol | Port(s) | Encryption | Transport | Primary Use |
|---|---|---|---|---|
| RADIUS | 1812 / 1813 | Password only | UDP | Network access control |
| TACACS+ | 49 | Full packet | TCP | Device administration |
| Diameter | 3868 | Full session | TCP / SCTP | Carrier / mobile networks |
| 802.1X | — | EAP-based | Layer 2 | Port-based access control |
TACACS+ encrypts the entire packet; RADIUS only encrypts the password field — a key exam distinction.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.