CAS-005 CompTIA SecurityX Certification Exam Free Practice Exam Questions (2025 Updated)

The key requirement is toinstantly eliminate data losson a lost device.

Cryptographic erasureworks by deleting encryption keys used for FDE (full disk encryption), rendering all data unrecoverable within seconds — satisfying the "mitigate within seconds" requirement.

Revoking certificates won’t wipe the data from a lost tablet.

Changing MFA credentials won’t help unless the device is secured, and app allow lists don’t apply post-loss.

FromCAS-005, Domain 3: Secure Systems Design and Deployment:

“Cryptographic erase (CE) renders data irrecoverable by deleting encryption keys used to protect data on the device.”

Step-by-Step Explanation:

Option A: Deny list

Deny lists block specific applications or processes identified as malicious.

This approach is reactive and mayinadvertently block the non-standard applications that are currently in use without proper ownership.

Option B: Allow list

Allow lists permit only pre-approved applications to run.

While secure, this approach requires defining all non-standard applications, which may disrupt operations in an environment where ownership is unclear.

Option C: Audit mode

Correct Answer.

Audit mode allows monitoring and logging of applications without enforcing restrictions.

This is ideal in environments with non-standard applications and undefined ownership because it enables the engineer to observe the environment and gradually implement control without interruption.

Audit mode provides critical visibility into the software landscape, ensuring that necessary applications remain functional.

Option D: MAC list

Mandatory Access Control (MAC) lists restrict access based on classification and clearance levels.

This does not align with application control objectives in this context.

CompTIA CASP+ Study Guide - Chapters on Endpoint Security and Application Control.

CASP+ Objective 2.4: Implement appropriate security controls for enterprise endpoints.

Comprehensive and Detailed Explanation:

Best practice in CAS-005 network security design is to deploy:

NIDS passively via a port mirror (SPAN port) to avoid introducing latency or failure points.

NIPS inline in a strategic point, such as integrated with the main firewall, to actively block threats.This combination provides both visibility and active protection without overloading network paths.

Step by Step Explanation:

Understanding the Scenario: The question is about ensuring that an organization retains control over its encryption keys. It focuses on different key storage and management methods.

Analyzing the Answer Choices:

A. Encrypting using a key stored in an on-premises hardware security module (HSM): This is thebest option for maintaining complete control over encryption keys. An HSM is a dedicated, tamper-resistant hardware device specifically designed for secure key storage and cryptographic operations. Storing keys on-premises within an HSM ensures the organization has exclusive access.

The log-in activity indicates a security threat, particularly involving the ADMIN account with a high-risk failure status. This suggests that the account may be targeted by malicious activities such as credential stuffing or brute force attacks.

Updating log configuration settings (A) may help in better logging future activities but does not address the immediate threat.

Changing the admin account password (B) is a good practice but may not fully mitigate the ongoing threat if the account has already been compromised.

Blocking employees (C) from logging into non-business applications might help in reducing attack surfaces but doesn't directly address the compromised account issue.

Implementing automation to disable accounts associated with high-risk activities ensures an immediate response to the detected threat, preventing further unauthorized access and allowing time for thorough investigation and remediation.

The security diagram proposed by the security architect depicts a Zero Trust security model. Zero Trust is asecurity framework that assumes all entities, both inside and outside the network, cannot be trusted and must be verified before gaining access to resources.

Key Characteristics of Zero Trust in the Diagram:

Role-based Access Control: Ensures that users have access only to the resources necessary for their role.

Mandatory Access Control: Additional layer of security requiring authentication for access to sensitive areas.

Network Access Control: Ensures that devices meet security standards before accessing the network.

Multi-factor Authentication (MFA): Enhances security by requiring multiple forms of verification.

This model aligns with the Zero Trust principles of never trusting and always verifying access requests, regardless of their origin.

Public Key Infrastructure (PKI) supports change management by securing messages (e.g., approvals, updates).Non-repudiation, provided via digital signatures, ensures a sender cannot deny sending a message, critical for auditability in change processes.

Option A:Correct—PKI’s digital signatures ensure non-repudiation.

Option B:Confidentiality (via encryption) is a PKI feature but less tied to change management’s focus on accountability.

Option C:Delivery receipts are not aPKI function; they’re protocol-specific (e.g., SMTP).

Option D:Attestation relates to verifying attributes, not a direct PKI message capability.

A. Implementing allow lists: Allow lists (whitelisting) restrict network communication to only authorized devices and applications, significantly reducing the attack surface by ensuring that only pre-approved traffic is permitted.

F. Implementing a site-to-site IPSec VPN: A site-to-site VPN provides a secure, encrypted tunnel for data transmission between the OT systems and the vendor, protecting the data from interception and tampering during transit.

Other options:

B. Monitoring network behavior: While useful for detecting anomalies, it does not proactively reduce the risk of compromise or sabotage.

C. Encrypting data at rest: Important for protecting data stored on devices, but does not address network communication risks.

D. Performing boot integrity checks: Ensures the integrity of the system at startup but does not protect ongoing network communications.

E. Executing daily health checks: Useful for maintaining system health but does not directly reduce the risk of network-based compromise or sabotage.

A proxy-based Cloud Access Security Broker (CASB) is chosen primarily for its ability to block unapproved applications and services. Here’s why:

Application and Service Control: Proxy-based CASBs can monitor and control the use of applications and services by inspecting traffic as it passes through the proxy. This allows the organization to enforce policies that block unapproved applications and services, ensuring compliance with security policies.

Visibility and Monitoring: By routing traffic through the proxy, the CASB can provide detailed visibility into user activities and data flows, enabling better monitoring and threat detection.

Real-Time Protection: Proxy-based CASBs can provide real-time protection against threats by analyzing and controlling traffic before it reaches the end user, thus preventing the use of risky applications and services.

Reviewing the asset inventory allows the security team to identify all instances of the affected application versions within the organization. By knowing which systems are running the vulnerable versions, the team can assess the full scope of the impact, determine which systems might be compromised, and prioritize them for further investigation and remediation.

Performing a port scan (Option A) might help identify open ports but does not provide specific information about theapplication versions. Inspecting egress network traffic (Option B) and analyzing user behavior (Option D) are important steps in the incident response process but do not directly identify which versions of the application are affected.

To prevent sensitive corporate information from being exposed if a laptop is stolen, the solution must ensure that data is not stored locally and access is tightly controlled. According to the CompTIA SecurityX CAS-005 study guide (Domain 4: Governance, Risk, and Compliance, 4.3), Desktop as a Service (DaaS) hosts data and applications in the cloud, reducing the risk of data exposure on physical devices. Combining DaaS with multifactor authentication (MFA) ensures that even if a laptop is stolen, unauthorized access to the cloud environment is prevented.

Option B:IP allow lists and SSO do not address data stored locally on the laptop, which could be accessed offline.

Option C:MDM and stronger passwords help but do not prevent data exposure if the device is compromised (e.g., via offline attacks).

Option D:Updating policies and monitoring breaches are reactive measures that do not directly protect data on a stolen laptop.

Option A:DaaS ensures no sensitive data resides on the device, and MFA secures access, making it the best solution.

When users disconnect from Remote Desktop Protocol (RDP) sessions without properly logging off, their sessions remain active on the server. If their passwords are changed due to the 90-day rotation policy, these lingering sessions may attempt to reauthenticate using outdated credentials, leading to multiple failed login attempts and potential account lockouts.

Automating the logout of inactive sessions ensures that disconnected or idle sessions are terminated after a specified period, preventing stale sessions from causing authentication issues. This approach aligns with best practices for session management and helps maintain security compliance.

Homomorphic encryption allows computations to be performed on encrypted data without decrypting it, providing strong privacy guarantees. However, the adoption of homomorphic encryption is challenging due to several factors:

A. Incomplete mathematical primitives: This is not the primary barrier as the theoretical foundations of homomorphic encryption are well-developed.

B. No use cases to drive adoption: There are several compelling use cases for homomorphic encryption, especially in privacy-sensitive fields like healthcare and finance.

C. Quantum computers not yet capable: Quantum computing is not directly related to the challenges of adopting homomorphic encryption.

D. Insufficient coprocessor support: The computational overhead of homomorphic encryption is significant, requiring substantial processing power. Current general-purpose processors are not optimized for the intensive computations required by homomorphic encryption, limiting its practical deployment. Specialized hardware or coprocessors designed to handle these computations more efficiently are not yet widely available.

Integrating IDS, firewall, and DLP to reduce response time requires orchestration and automation. Let’s evaluate:

A. SOAR(Security Orchestration, Automation, and Response):SOAR integrates security tools, automates workflows, and speeds up incident response. It’s the best fit for this scenario, as CAS-005 highlights SOAR for operational efficiency.

B. CWPP (CloudWorkload Protection Platform):Focused on securing cloud workloads, not integrating on-premises tools.

C. XCCDF (Extensible Configuration Checklist Description Format):A standard for compliance checklists, not a tool for integration or response.

Input sanitation is a critical process in cybersecurity that involvesvalidating and cleaning data provided by users to prevent malicious inputs from causing harm. In the context of AI concerns:

A. Model inversion involves an attacker inferring sensitive data from model outputs, typically requiring sophisticated methods beyond just manipulating input data.

B. Prompt Injection is a form of attack where an adversary provides malicious input to manipulate the behavior of AI models, particularly those dealing with natural language processing (NLP). Input sanitation directly addresses this by ensuring that inputs are cleaned and validated to remove potentially harmful commands or instructions that could alter the AI's behavior.

C. Data poisoning involves injecting malicious data into the training set to compromise the model. While input sanitation can help by filtering out bad data, data poisoning is typically addressed through robust data validation and monitoring during the model training phase, rather than real-time input sanitation.

D. Non-explainable model refers to the lack of transparency in how AI models make decisions. This concern is not addressed by input sanitation, as it relates more to model design and interpretability techniques.

Input sanitation is most relevant and effective for preventing Prompt Injection attacks, where the integrity of user inputs directly impacts the performance and security of AI models.

The table shows that the user "SALES1" is consistently blocked despite having met the MFA requirements. The common factor in these blocked attempts is the source IP address (8.11.4.16) being identified as from Germany while the user is assigned to France. This discrepancy suggests that the network geolocation is being misidentified by the authentication server, causing legitimate access attempts to be blocked.

Why Network Geolocation Misidentification?

Geolocation Accuracy: Authentication systems often use IP geolocation to verify the location of access attempts. Incorrect geolocation data can lead to legitimate requests being denied if they appear to come from unexpected locations.

Security Policies: Company security policies might block access attempts from certain locations to prevent unauthorized access. If the geolocation is wrong, legitimate users can be inadvertently blocked.

Consistent Pattern: The user "SALES1" from the IP address 8.11.4.16 is always blocked, indicating a consistent issue with geolocation.

Other options do not align with the pattern observed:

A. Bypass MFA requirements: MFA is satisfied, so bypassing MFA is not the issue.

C. Administrator access policy: This is about user access, not specific administrator access.

D. OTP codes: The user has satisfied MFA, so OTP code configuration is not the issue.

The most appropriate technique to improve the cryptographic strength of a password-storage component in a web application without completely replacing the crypto-module is key stretching. Here's why:

Enhanced Security: Key stretching algorithms, such as PBKDF2, bcrypt, and scrypt, increase the computational effort required to derive the encryption key from the password, making brute-force attacks more difficult and time-consuming.

Compatibility: Key stretching can be implemented alongside existing cryptographic modules, enhancing their security without the need for a complete overhaul.

Industry Best Practices: Key stretching is a widely recommended practice for securely storing passwords, as it significantly improves resistance to password-cracking attacks.

In the context of establishing a Security Operations Center (SOC) with a threat-modeling function, it's crucial to understand how data flows within the organization's systems. Network and data flow diagrams provide a visual representation of the system's architecture, illustrating how data moves between components, which is essential for identifying potential security weaknesses and antipatterns. Antipatterns are common responses to recurring problems that are ineffective and risk-inducing. By analyzing these diagrams, the consultant can pinpoint areas where security controls may be lacking or misconfigured, thereby facilitating the development of effective threat models.​

While other options like unpatchable IoT devices (Option B) and inventories of cloud resources (Option E) are important for comprehensive security assessments, they are more pertinent during later stages, such as vulnerability management and asset inventory. The initial phase of threat modeling focuses on understanding the system's structure and data flows to identify potential threats, making network and data flow diagrams the most critical information at this stage.​

To ensure the most secure way of keeping a legacy system (COL) operating until a new solution is available, isolating the system and enforcing strict firewall rules is the best approach. This method minimizes the attack surface by restricting access to only the necessary endpoints, thereby reducing the risk of unauthorized access and potential security breaches. Isolating the system ensures that it is not exposed to the broader network, while firewall rules control the traffic that can reach the system, providing a secure environment until a replacement is implemented.