hardMultiple ChoiceObjective-mapped
CAS-004 Practice Question: A large enterprise is migrating its critical…
A large enterprise is migrating its critical financial applications to a public cloud provider. The security architecture team has designed a multi-region deployment to ensure availability and disaster recovery. The applications use TLS for data in transit and rely on a key management service (KMS) for encryption keys. During a penetration test, it was discovered that the KMS master keys are stored in a single region, creating a single point of failure. Additionally, the load balancer configuration exposes internal application health check ports to the internet. The security architect must remediate these issues while minimizing latency and cost. Which of the following is the BEST course of action?
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
✓
Implement cross-region replication of KMS master keys and restrict health check ports to internal IP ranges only
The best course of action because it directly addresses both security issues: cross-region replication of KMS master keys eliminates the single point of failure, and restricting health check ports to internal IP ranges reduces exposure. Option A is incorrect because it replaces TLS with IPsec (unnecessary) and adds complexity. Option C consolidates to one region, which defeats the purpose of multi-region deployment for availability and disaster recovery. Option D embeds keys in code, violating key management best practices. Option B minimizes latency and cost while ensuring security.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Replace the TLS encryption with IPsec VPNs and use a third-party key management appliance in each region
Why it's wrong here
Unnecessary complexity; TLS is sufficient and IPsec may increase latency.
- ✓
Implement cross-region replication of KMS master keys and restrict health check ports to internal IP ranges only
Why this is correct
Replication ensures key availability; restricting health check ports reduces attack surface.
- ✗
Move all applications to a single region to simplify key management and use a single shared load balancer
Why it's wrong here
Eliminates disaster recovery and increases risk of regional failure.
- ✗
Use client-side encryption with keys stored in the application code and disable the health checks entirely
Why it's wrong here
Storing keys in code is insecure; disabling health checks may cause availability issues.
Quick reference
VPN Protocol Comparison
| Protocol | Port | Encryption | Authentication | Use Case |
|---|---|---|---|---|
| IKEv2 / IPsec | UDP 500 / 4500 | AES-256 | Certificates / PSK | Site-to-site & remote access |
| SSL / TLS VPN | TCP 443 | TLS 1.3 | Certificates / MFA | Clientless remote access |
| L2TP / IPsec | UDP 1701 | AES (IPsec) | PSK / Certificates | Legacy remote access |
| WireGuard | UDP 51820 | ChaCha20 | Public keys | Modern high-performance VPN |
| PPTP | TCP 1723 | MPPE (weak) | MS-CHAPv2 | Legacy — avoid in production |
PPTP is considered insecure. IKEv2/IPsec and SSL VPN are the current recommended options.
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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.