CAS-004 Practice Test 2 — 30 Questions

Question 1

Refer to the exhibit. A security engineer reviews the S3 bucket policy. Which of the following is the most concerning security issue?

Accepted Answer

The policy allows public read access to all objects in the bucket. The S3 bucket policy explicitly grants the `s3:GetObject` action to `"Principal": "*"`, which allows any unauthenticated user (public) to read all objects in the bucket. This is a critical misconfiguration that exposes sensitive data to the internet, often leading to data breaches. The policy does not restrict access by IP, referer, or any condition, making it a direct violation of the principle of least privilege.

Answer

The policy does not require encryption in transit

Answer

The policy uses the incorrect version of the policy language

Answer

The policy allows any user to list the objects in the bucket

Question 2

An organization needs to ensure consistent configuration across multiple Linux servers. They want to automate this process with a solution that requires minimal agent installation and uses push-based communication. Which approach is most appropriate?

Accepted Answer

Use Ansible playbooks to define and enforce server configurations.. Ansible is the most appropriate choice because it is agentless (no agent installation required) and uses push-based communication over SSH to enforce configurations. It uses YAML-based playbooks to define desired states, making it ideal for automating consistent configuration across multiple Linux servers with minimal overhead.

Answer

Use PowerShell Desired State Configuration (DSC) with Linux extensions.

Answer

Run a Docker container on each server with a configuration management tool inside.

Answer

Deploy Puppet with a master server and agents on each system.

Question 3

A security architect is designing a cloud security strategy for a company that uses multiple cloud providers. The architect needs a solution that provides visibility into cloud application usage, enforces security policies, and protects data. Which technology is most appropriate?

Accepted Answer

Cloud Access Security Broker (CASB). A Cloud Access Security Broker (CASB) provides visibility, policy enforcement, and data protection across multiple cloud services.

Answer

Cloud Workload Protection Platform (CWPP)

Answer

Cloud Security Posture Management (CSPM)

Answer

Secure Access Service Edge (SASE)

Question 4

A company is migrating its monolithic application to a microservices architecture. The security team wants to implement controls to protect inter-service communication and ensure data integrity. Which THREE security controls should be implemented? (Select THREE.)

Accepted Answer

Deploy an API gateway to enforce rate limiting and authentication. An API gateway acts as a single entry point for all service calls, enforcing rate limiting to prevent abuse and authentication (e.g., OAuth2, JWT) to verify identity before requests reach backend microservices. This centralizes security policy enforcement and protects inter-service communication by reducing the attack surface.

Option C is correct because mutual TLS (mTLS) provides strong service-to-service authentication and encryption for data in transit. With mTLS, each service presents a certificate to verify its identity, and the TLS handshake ensures all communication is encrypted and integrity-protected, preventing eavesdropping and man-in-the-middle attacks.

Option D is correct because a container orchestration platform (e.g., Kubernetes) can enforce network policies that restrict communication between services, ensuring only authorized service-to-service interactions. This provides an additional layer of security for inter-service communication beyond the API gateway and mTLS.

Answer

Encrypt data at rest using AES-256

Answer

Conduct static code analysis on all microservices

Question 5

An engineer reviews the TLS configuration for a web server, which includes the following line:
ssl_verify_client optional;
Which of the following is a security concern present in this configuration?

Accepted Answer

The server does not require client certificates for authentication.. The TLS configuration sets ssl_verify_client to optional, allowing clients to connect without a certificate. This undermines mutual TLS (mTLS) enforcement, leaving the server vulnerable to unauthorized access if client authentication is expected. Option A is incorrect; perfect forward secrecy is provided by modern cipher suites, and its absence is not a concern here. Option B is incorrect; TLS 1.2 and 1.3 are industry-standard secure protocols. Option C is incorrect; the private key path is outside the document root and properly secured, which is a typical configuration.

Answer

The cipher suite does not include perfect forward secrecy (PFS).

Answer

The configuration supports outdated TLS 1.2 protocols.

Answer

The private key is stored in an accessible location.

Question 6

A security analyst discovers that a third-party vendor has been granted access to the company's production database for support purposes. The vendor's contract expires in two weeks. What is the BEST course of action to ensure compliance with the principle of least privilege and reduce risk?

Accepted Answer

Immediately revoke the vendor's database access and provide temporary access only if needed.. The principle of least privilege requires that access rights be granted only for the minimum necessary duration. Since the vendor's contract expires in two weeks, there is no ongoing business need for continued access. Immediately revoking access and providing temporary access only if needed ensures that the vendor cannot access the production database after the contract ends, reducing the risk of unauthorized data exposure or malicious activity.

Answer

Extend the contract for another year to maintain support continuity.

Answer

Wait until the contract expires and then revoke access.

Answer

Monitor the vendor's activities until the contract expires.

Question 7

A security analyst is reviewing alerts from a SIEM and notices multiple failed login attempts from a single IP address to different user accounts over a 5-minute window. What should the analyst do FIRST?

Accepted Answer

Check the source IP and correlate with other logs to confirm suspicious activity.. In incident response, the first step is to verify the alert before taking any action. The analyst should check the source IP and correlate the failed login attempts with other logs (e.g., VPN logs, IDS alerts, or previous successful logins) to determine if this is a brute-force attack, a misconfigured application, or a false positive. Prematurely blocking the IP (option A) could disrupt legitimate traffic if the IP is a shared proxy or NAT. Isolating endpoints (option B) is excessive without confirmation that the attempts were successful or that the endpoints are compromised. Resetting all targeted accounts (option D) is disruptive and unnecessary without evidence of compromise. Therefore, the correct first step is to verify and correlate the alert (option C).

Answer

Block the IP address at the firewall.

Answer

Isolate all endpoints that received the login attempts.

Answer

Reset all user accounts that were targeted.

Question 8

An incident response team is handling a ransomware incident. The team has successfully contained the threat and is now in the eradication phase. Which THREE actions are appropriate for the eradication phase? (Select THREE.)

Accepted Answer

Apply security patches to the vulnerability that allowed initial access. Eradication involves removing the threat completely: deleting malware, revoking compromised credentials, and patching vulnerabilities.

Answer

Restore systems from clean backups

Answer

Conduct a lessons learned meeting

Question 9

A DevOps team is automating the deployment of a containerized application to production. Which THREE practices are essential for maintaining security and reliability? (Select THREE.)

Accepted Answer

Use Helm charts to package and deploy Kubernetes applications.. Helm charts are essential for packaging and deploying Kubernetes applications because they provide a standardized, version-controlled way to manage complex Kubernetes manifests. Helm simplifies deployment, rollback, and dependency management, which is critical for maintaining security and reliability in production environments.

Answer

Use Docker Compose files for production deployments.

Answer

Manually configure each environment to handle unique settings.

Question 10

Which THREE of the following are effective techniques for detecting advanced persistent threats (APTs) within a network? (Select exactly 3.)

Accepted Answer

Conducting behavioral analysis of endpoint and network activity to detect unusual patterns.. Behavioral analysis (option B) is effective against APTs because it establishes a baseline of normal activity and flags deviations, such as unusual lateral movement or data exfiltration patterns, which APTs often exhibit. Unlike signature-based methods, behavioral analysis can detect novel or zero-day attack techniques that do not match known signatures, making it a critical component of an advanced threat detection strategy.

Answer

Using signature-based intrusion detection systems (IDS) to match known attack patterns.

Answer

Deploying honeypots to attract and analyze attacker behavior.

Question 11

Drag and drop the steps to perform a secure code review for a web application into the correct order.

Accepted Answer

Step 1: Understand the codebase, Step 2: Run automated scanning tools, Step 3: Perform manual code review, Step 4: Document and communicate findings. Secure code review: understand code, automated scan, manual review, document, and communicate findings.

Answer

Step 1: Run automated scanning tools, Step 2: Understand the codebase, Step 3: Perform manual code review, Step 4: Document and communicate findings

Answer

Step 1: Understand the codebase, Step 2: Perform manual code review, Step 3: Run automated scanning tools, Step 4: Document and communicate findings

Answer

Step 1: Understand the codebase, Step 2: Run automated scanning tools, Step 3: Document and communicate findings, Step 4: Perform manual code review

Question 12

During a security assessment, the engineer discovers that a network appliance's firmware updates are signed using a 1024-bit RSA key. The appliance was manufactured in 2015. What is the primary security concern?

Accepted Answer

The key length is insufficient against modern attacks. A 1024-bit RSA key is considered insufficient against modern attacks due to advances in factoring algorithms and computational power. By 2015, NIST and industry standards already recommended a minimum of 2048-bit RSA keys for secure digital signatures, making the 1024-bit key vulnerable to factorization attacks, especially with resources like the CADO-NFS or AWS clusters.

Answer

The firmware is not encrypted

Answer

The signature algorithm is obsolete

Answer

The signing key is not rotated

Question 13

Which three options are best practices for writing secure scripts? (Choose three.)

Accepted Answer

Use parameterized inputs to prevent injection attacks.. Parameterized inputs (also known as prepared statements or parameterized queries) separate SQL or shell command logic from user-supplied data, ensuring that input is treated strictly as data, not executable code. This prevents injection attacks such as SQL injection or command injection, which occur when untrusted input is concatenated directly into a command string. In scripting languages like Python, using `cursor.execute("SELECT * FROM users WHERE id = ?", (user_id,))` instead of string formatting eliminates the risk of an attacker breaking out of the intended syntax.

Answer

Log all errors and warnings for debugging.

Answer

Hardcode sensitive credentials in the script.

Question 14

Given the exhibit, what is the effect of this S3 bucket policy on an object stored in 'bucket-name'?

Accepted Answer

All requests to the bucket are denied regardless of source IP.. The S3 bucket policy includes an explicit Deny statement that denies all actions (s3:*) for all principals (*), effectively blocking any request regardless of source IP. Even though there is an Allow statement permitting GetObject from the 10.0.0.0/8 range, the explicit Deny overrides it due to the policy evaluation logic where Deny takes precedence over Allow. Therefore, all requests to the bucket are denied.

Answer

Requests from outside 10.0.0.0/8 are allowed to read objects.

Answer

All requests from IPs in 10.0.0.0/8 are allowed to read objects.

Answer

Only anonymous requests are denied.

Question 15

During a forensic investigation, an analyst finds that a compromised system's memory dump shows signs of a kernel-mode rootkit. Which technique is MOST effective to detect the rootkit without relying on the compromised OS?

Accepted Answer

Perform memory analysis using volatility on an isolated forensic workstation.. Memory forensics on a different system enables analysis of the memory dump without relying on the compromised OS, allowing detection of kernel-mode rootkits that hide from OS-level tools. Option A (antivirus on disk image) depends on the compromised OS and may miss rootkits that hide from file system scans. Option B (registry snapshots) is ineffective because kernel rootkits operate below the registry level and can manipulate or avoid registry entries. Option C (network packet captures) may show C2 traffic but does not directly detect the rootkit itself, and many rootkits use encrypted communication.

Answer

Run antivirus scans on the disk image.

Answer

Compare registry snapshots before and after infection.

Answer

Analyze network packet captures for C2 traffic.

Question 16

A company wants to reduce the mean time to detect (MTTD) for security incidents. Which technology is most effective for this purpose?

Accepted Answer

Security information and event management (SIEM) with behavior analytics. A SIEM with User and Entity Behavior Analytics (UEBA) is most effective for reducing MTTD because it baselines normal behavior and detects anomalies in real time, enabling early detection of threats. Full disk encryption (B) protects data at rest but does not aid detection. A DLP system (C) focuses on preventing data exfiltration, not broad detection. A NIDS (D) relies on signature matching, which can miss novel or subtle attacks and typically has a higher detection latency than behavior analytics.

Answer

Full disk encryption software

Answer

Data loss prevention (DLP) system

Answer

Network-based intrusion detection system (NIDS)

Question 17

Refer to the exhibit. A security engineer is reviewing an X.509 certificate used for TLS. Which security concern should the engineer identify?

Accepted Answer

The certificate uses the SHA-1 hash algorithm. The certificate uses the SHA-1 hash algorithm, which is cryptographically broken and vulnerable to collision attacks. SHA-1 is deprecated by major browsers and the CA/Browser Forum, and its use in TLS certificates poses a significant security risk because an attacker could forge a certificate with the same hash.

Answer

The RSA key length is 2048 bits

Answer

The certificate is self-signed

Answer

The validity period is only one year

Question 18

A security engineer is evaluating the use of AES-256-GCM for encrypting sensitive data in transit. They note that the Additional Authenticated Data (AAD) field is empty. What is the security implication?

Accepted Answer

The cipher is secure, but the missing AAD may allow an attacker to replace the ciphertext with another valid ciphertext from a different context, causing a potential mix-and-match attack.. In AES-256-GCM, the Additional Authenticated Data (AAD) provides context binding, ensuring that the ciphertext is authentic only within a specific context (e.g., a particular session or transaction). When AAD is empty, an attacker who has access to multiple valid ciphertexts (each with its own context) could potentially swap them without detection, leading to a mix-and-match attack. The cipher still provides authentication (via the authentication tag) and confidentiality, but without AAD, the binding to the intended context is lost. Option B is wrong because missing AAD does not directly affect protection against man-in-the-middle attacks; the cipher still provides integrity and authentication. Option C is wrong because AES-256-GCM provides authentication through its GMAC authentication tag, even without AAD. Option D is wrong because AAD has no impact on key recovery; GCM is secure against key recovery attacks regardless of AAD.

Answer

The cipher is still secure, but missing AAD offers no additional protection against man-in-the-middle attacks.

Answer

The encryption provides no authentication because AAD is missing.

Answer

The cipher becomes vulnerable to key recovery attacks because AAD is missing.

Question 19

A small business uses Puppet for configuration management on Linux servers. They are now migrating to containers and want to maintain security. The operations team is unfamiliar with containers. The security team insists on automated vulnerability scanning of container images before deployment. What should be the company's first step?

Accepted Answer

Create a hardened base image standard, and set up a CI pipeline that automatically scans every image for vulnerabilities before it is pushed to the registry.. The first step in securing container images is to establish a hardened base image standard and integrate vulnerability scanning into a CI pipeline. This ensures that every image is automatically checked for known vulnerabilities before being pushed to the registry, addressing the security team's requirement without requiring the operations team to immediately master container orchestration. This approach aligns with the principle of shifting security left, preventing vulnerable images from ever reaching production.

Answer

Deploy a Kubernetes cluster and migrate all applications.

Answer

Discontinue using Puppet and switch entirely to container-based configurations.

Answer

Train the operations team on Docker and Kubernetes fundamentals.

Question 20

A security analyst is reviewing a CI/CD pipeline configuration. The pipeline uses a containerized application and includes automated security scanning. Which TWO practices should be implemented to ensure container immutability and reduce the attack surface?

Accepted Answer

Run containers with read-only root filesystem.. Running containers with a read-only root filesystem enforces immutability, preventing any modifications at runtime. Option B is correct because scanning images for vulnerabilities at build time reduces the attack surface by catching issues before deployment. Option C is incorrect because using the same base image for all environments does not directly relate to immutability or attack surface reduction and may ignore environment-specific security needs. Option D is incorrect because running containers as root weakens security and increases the attack surface. Option E is incorrect because storing credentials in environment variables is insecure and should be avoided.

Answer

Use the same base image for all environments.

Answer

Run containers as root.

Answer

Store credentials in environment variables.