CAS-004 CompTIA SecurityX Certification Exam Free Practice Exam Questions (2025 Updated)

Public keys on both endpoints are required for implementing PKI-based mutual authentication. PKI stands for Public Key Infrastructure, which is a system that manages the creation, distribution, and verification of certificates. Certificates are digital documents that contain public keys and identity information of their owners. Certificates are issued by trusted authorities called Certificate Authorities (CAs), and can be used to prove the identity and authenticity of the certificate holders. Mutual authentication is a process in which two parties authenticate each other at the same time using certificates. Mutual authentication can provide stronger security and privacy than one-way authentication, where only one party is authenticated. In PKI-based mutual authentication, each party has a certificate that contains its public key and identity information, and a private key that corresponds to its public key. The private key is kept secret and nevershared with anyone, while the public key is shared and used to verify the identity and signature of the certificate holder. The basic steps of PKI-based mutual authentication are as follows:

Party A sends its certificate to Party B.

Party B verifies Party A’s certificate by checking its validity, signature, and trust chain. If the certificate is valid and trusted, Party B extracts Party A’s public key from the certificate.

Party B generates a random challenge (such as a nonce or a timestamp) and encrypts it with Party A’s public key. Party B sends the encrypted challenge to Party A.

Party A decrypts the challenge with its private key and sends it back to Party B.

Party B compares the received challenge with the original one. If they match, Party B confirms that Party A is the legitimate owner of the certificate and has possession of the private key.

The same steps are repeated in reverse, with Party A verifying Party B’s certificate and sending a challenge encrypted with Party B’s public key.

A. Perfect forward secrecy on both endpoints is not required for implementing PKI-based mutual authentication. Perfect forward secrecy (PFS) is a property of encryption protocols that ensures that the compromise of a long-term secret key (such as a private key) does not affect the security of past or future session keys (such as symmetric keys). PFS can enhance the security and privacy of encrypted communications, but it does not provide authentication by itself.

B. Shared secret for both endpoints is not required for implementing PKI-based mutual authentication. Shared secret is a method of authentication that relies on a pre-shared piece of information (such as a password or a passphrase) that is known only to both parties. Shared secret can provide simple and fast authentication, but it does not provide non-repudiation or identity verification.

D. A common public key on each endpoint is not required for implementing PKI-based mutual authentication. A common public key on each endpoint would imply that both parties share the same certificate and private key, which would defeat the purpose of PKI-based mutual authentication. Each party should have its own unique certificate and private key that proves its identity and authenticity.

E. A common private key on each endpoint is not required for implementing PKI-based mutual authentication. A common private key on each endpoint would imply that both parties share the same certificate and public key, which would defeat the purpose of PKI-based mutual authentication. Each party should have its own unique certificate and private key that proves its identity and authenticity.

A source code escrow is a legal agreement that involves a third party holding the source code of a software application on behalf of the software vendor and the software licensee. The source code escrow ensures that the licensee can access the source code in case the vendor goes out of business, fails to provide maintenance or support, or breaches the contract terms.

A source code escrow would have prevented the risk of having an old application that is not covered for maintenance anymore because the software company is no longer in business, because it would:

Allow the licensee to obtain the source code and continue to update, fix, or modify the application according to their needs.

Protect the vendor’s intellectual property rights and prevent unauthorized disclosure or use of the source code.

Provide a legal framework and a trusted mediator for resolving any disputes or issues between the vendor and the licensee.

The change control board (CCB) is a committee that consists of subject matter experts and managers who decide whether to implement proposed changes to a project. The change control board is part of the change management plan, which defines the roles and processes for managing change within a team or organization. The change control board must review and approve a submission for any change request that affects the scope, schedule, budget, quality, or risks of the project. The change control board evaluates the impact and benefits of the change request and decides whether to accept, reject, or defer it.

A. The implementation engineer requesting direct approval from the systems engineer and the Chief Information Security Officer is not a correct process for requesting updates or corrections to the client’s systems, because it bypasses the change control board and the project manager. This could lead to unauthorized changes that could compromise the project’s objectives and deliverables.

C. The information system security officer providing the systems engineer with the system updates is not a correct process for requesting updates or corrections to the client’s systems, because it does not involve the change control board or the project manager. This could lead to unauthorized changes that could introduce security vulnerabilities or conflicts with other system components.

D. The security engineer asking the project manager to review the updates for the client’s system is not a correct process for requesting updates or corrections to the client’s systems, because it does not involve the change control board. The project manager is responsible for facilitating the change management process, but not for approving or rejecting change requests.

https://www.projectmanager.com/blog/change-control-board-roles-responsibilities-processes

The organization is implementing homomorphic encryption. Homomorphic encryption is a type of encryption that allows computations to be performed on encrypted data without decrypting it first. This means that the organization can analyze the customers’ data and deliver analysis results without being able to see the raw data, preserving the privacy and confidentiality of the customers. Homomorphic encryption can enable various applications, such as cloud computing, machine learning, and data analytics, that require processing sensitive data without compromising security. Verified References:

https://www.techtarget.com/searchsecurity/definition/homomorphic-encryption

https://learn.microsoft.com/en-us/azure/security/fundamentals/encryption-at-rest

https://www.ibm.com/topics/homomorphic-encryption

Wireless network auto joining is the mobile configuration setting that the mobile administrator is verifying by reviewing the mobile device DHCP logs. Wireless network auto joining is a feature that allows mobile devices to automatically connect to a predefined wireless network without requiring user intervention or authentication. This can be useful for corporate or trusted networks that need frequent access by mobile devices. The DHCP logs show that the mobile devices are assigned IP addresses from the wireless network with SSID “CorpWiFi”, which indicates that they are auto joining this network.

The most likely cause of the signature failing is that the certificate is set for the wrong key usage. Key usage is an extension of a certificate that defines the purpose and functionality of the public key contained in the certificate. Key usage can include digital signature, key encipherment, dataencipherment, certificate signing, and others. If the certificate is set for a different key usage than digital signature, it will not be able to sign the applications properly. The administrator should check the key usage extension of the certificate and make sure it matches the intended purpose. Verified References:

https://www.wintips.org/how-to-fix-windows-cannot-verify-the-digital-signature-for-this-file-error-in-windows-8-7-vista/

https://softwaretested.com/mac/how-to-fix-a-digital-signature-error-on-windows-10/

https://support.microsoft.com/en-us/office/digital-signatures-and-certificates-8186cd15-e7ac-4a16-8597-22bd163e8e96

Execute never is a technology that can be enabled on the ARM architecture to prevent malware from inserting itself in another process’ memory location. Execute never (also known as XN or NX) is a feature that marks certain memory regions as non-executable, meaning that they cannot be used to run code. This prevents malware from exploiting buffer overflows or other memory corruption vulnerabilities to inject malicious code into another process’ memory space.

SD-WAN (Software-Defined Wide Area Network) is a technology that allows organizations to use multiple, low-cost Internet connections to create a secure and dynamic WAN. SD-WAN can provide benefits such as lower costs, higher performance, and easier management compared to traditional WAN technologies, such as MPLS (Multiprotocol Label Switching).

However, SD-WAN also introduces some potential risks, such as:

The reliability and security of the Internet connections, which may vary depending on the location, provider, and traffic conditions.

The compatibility and interoperability of the SD-WAN hardware and software, which may come from different vendors or use different standards.

The availability and quality of the SD-WAN provider’s support, which may depend on the provider’s size, reputation, and outsourcing practices.

In this case, the CISO would most likely identify the risk that the SD-WAN provider uses a third party for support, because this could:

Affect the organization’s ability to resolve issues or request changes in a timely and effective manner.

Expose the organization’s network data and configuration to unauthorized or malicious parties.

Increase the complexity and uncertainty of the SD-WAN service level agreement (SLA) and contract terms.

A content delivery network (CDN) is a geographically distributed network of servers that can cache content close to end users, allowing for faster and more efficient delivery of web content, such as images, videos, and streaming media. A CDN can also handle an increase in customer demand of resources, provide high-quality streaming media, and create a user-friendly interface by reducing latency and bandwidth consumption. A CDN can also improve the security and availability of the website by mitigating DDoS attacks and providing redundancy. Verified References:

https://www.cloudflare.com/learning/cdn/what-is-a-cdn/

https://learn.microsoft.com/en-us/azure/cdn/cdn-overview

https://en.wikipedia.org/wiki/Content_delivery_network

 Disabling file exchange can help to minimize data leakage by preventing users from sharing sensitive documents or data through the videoconferencing platform. Enabling watermarking can help to maintain customer trust and ensure non-repudiation by adding a visible or invisible mark to the video stream that identifies the source or owner of the content. Enabling the user authentication requirement can help to secure the videoconferencing sessions by verifying the identity of the participants and preventing unauthorized access. Verified References:

https://www.rev.com/blog/marketing/follow-these-7-video-conferencing-security-best-practices

https://www.paloaltonetworks.com/blog/2020/04/network-video-conferencing-security/

https://www.megameeting.com/news/best-practices-secure-video-conferencing/

The root cause of this issue is that the iOS keychain imported only the client public and private keys, but not the CA certificate. A PKCS#12 file (.p12 or .pfx) is a file format that contains a certificate and its private key, optionally protected by a password. A PKCS#12 file can also contain intermediate certificates or root certificates that are needed to verify the certificate chain. However, when importing a PKCS#12 file into the iOS keychain, only the certificate and its private key are imported, not the CA certificate. This means that the iOS device cannot verify the authenticity of the certificate, and displays the error message “mbedTLS: ca certificate undefined”. To fix this issue, the CA certificate needs to be imported separately into the iOS keychain, either manually or using a configuration profile. Verified References:

https://developer.apple.com/documentation/devicemanagement/certificatepkcs12

https://support.apple.com/guide/deployment/distribute-certificates-depcdc9a6a3f/web

https://openvpn.net/faq/how-do-i-use-a-client-certificate-and-private-key-from-the-ios-keychain/

Resource exhaustion is a condition that occurs when a system or service runs out of resources, such as memory, CPU, disk space, or bandwidth, and becomes unable to function properly or respond torequests. Resource exhaustion can be caused by high demand, poor design, misconfiguration, or malicious attacks, such as denial-of-service (DoS).

Resource exhaustion would be the most significant business risk to a company that signs a contract with a cloud service provider (CSP) that is able to provide the same uptime as other CSPs at a markedly reduced cost, because this could:

Indicate that the CSP is oversubscribing or underprovisioning its resources, which could result in performance degradation, service disruption, or data loss for the company.

Affect the company’s availability, reliability, and scalability requirements, which could impact its operations, reputation, and customer satisfaction.

Expose the company to potential security breaches or compliance violations, if the CSP does not implement adequate security controls or measures to prevent or mitigate resource exhaustion.

Defining ACLs in a CSP relies on software-defined networking. Software-defined networking (SDN) is a network architecture that decouples the control plane from the data plane, allowing for centralized and programmable network management. SDN can enable dynamic and flexible network configuration and optimization, as well as improved security and performance. In a CSP, SDN can be used to define ACLs that can apply to virtual networks, subnets, or interfaces, regardless of the physical infrastructure. SDN can also allow for granular and consistent ACL enforcement across different cloud services and regions. Verified References:

https://www.techtarget.com/searchsdn/definition/software-defined-networking-SDN

https://learn.microsoft.com/en-us/azure/architecture/guide/networking/network-security

https://www.techtarget.com/searchcloudcomputing/definition/cloud-networking

The company should implement an EV certificate and HSTS on its new website. An EV certificate provides the highest level of web identity validation by requiring extensive verification of the organization’s identity and domain ownership. HSTS enforces encryption of all web transactions by redirecting HTTP requests to HTTPS and preventing users from accepting invalid certificates. These solutions would enhance the security and trustworthiness of the website without increasing complexity or expenditure significantly. Verified References:

https://www.entrust.com/digital-security/certificate-solutions/products/digital-certificates/tls-ssl-certificates

https://learn.microsoft.com/en-us/azure/active-directory/develop/access-tokens

Containerization is a technology that allows applications to run in isolated and portable environments called containers. Containers are lightweight and self-contained units that include all the dependencies, libraries, and configuration files needed for an application to run. Containers can be deployed on any platform that supports the container runtime engine, such as Docker or Kubernetes.

Containerization would allow the company to refactor a monolithic application to take advantage of cloud native services and service microsegmentation to secure sensitive application components, because containerization would:

Enable the application to be split into smaller and independent components (microservices) that can communicate with each other through APIs or message queues.

Allow the application to leverage cloud native services, such as load balancers, databases, or serverless functions, that can be integrated with containers through configuration files or environment variables.

Enhance the security of the application by isolating each container from other containers and the host system, and applying fine-grained access control policies and network rules to each container or group of containers.

Ensure the portability of the application by enabling it to run on any cloud provider or platform that supports containers, without requiring any changes to the application code or configuration.

SaaS, or software as a service, is the solution that can best fulfill the requirements of having the lowest RTO possible, the least shared responsibility possible, and patching as a responsibility of the CSP. SaaS is a cloud service model that provides users with access to software applications hosted and managed by the CSP over the internet. SaaS has the lowest RTO (recovery time objective), which is the maximum acceptable time for restoring a system or service after a disruption, because it does not require any installation, configuration, or maintenance by the users. SaaS also has the least shared responsibility possible because most of the security aspects are handled by the CSP, such as patching, updating, backup, encryption, authentication, etc.

DMARC (Domain-based Message Authentication, Reporting and Conformance) and SPF (Sender Policy Framework) are two mechanisms that can help detect and prevent email spoofing, which is the creation of email messages with a forged sender address. DMARC allows a domain owner to publish a policy that specifies how receivers should handle messages that fail authentication tests, such as SPF or DKIM (DomainKeys Identified Mail). SPF allows a domain owner to specify which mail servers are authorized to send email on behalf of their domain. By checking the DMARC and SPF records of the sender’s domain, a receiver can verify if the email is from a legitimate source or not. Verified References:

https://en.wikipedia.org/wiki/Email_spoofing

https://en.wikipedia.org/wiki/DMARC

https://en.wikipedia.org/wiki/Sender_Policy_Framework

Key escrow is a process that involves storing encryption keys with a trusted third party, such as a CASB (Cloud Access Security Broker) or a government agency. Key escrow can enable authorized access to encrypted data in case of emergencies, legal issues, or data recovery. However, key escrow also introduces some risks and challenges, such as trust, security, and privacy.References: https://www.techopedia.com/definition/1772/key-escrow https://searchsecurity.techtarget.com/definition/key-escrow

Assuring the integrity of messages is the most important security objective when applying cryptography to control messages that tell an ICS (industrial control system) how much electrical power to output. Integrity is the security objective that ensures the accuracy and completeness of data or information, preventing unauthorized modifications or tampering. Assuring the integrity of messages can prevent malicious or accidental changes to the control messages that could affect the operation or safety of the ICS or the electrical power output. Importing the availability of messages is not a security objective when applying cryptography, but a security objective that ensures the accessibility and usability of data or information, preventing unauthorized denial or disruption of service. Ensuring non-repudiation of messages is not a security objective when applying cryptography, but a security objective that ensures the authenticity and accountability of data or information, preventing unauthorized denial or dispute of actions or transactions. Enforcing protocol conformance for messages is not a security objective when applying cryptography, but a security objective that ensures the compliance and consistency of data or information, preventing unauthorized deviations or violations of rules or standards. VerifiedReferences: https://www.comptia.org/blog/what-is-integrity https://partners.comptia.org/docs/default-source/resources/casp-content-guide

A screened subnet is a network segment that separates two different environments, such as ОТ (operational technology) and IT (information technology), and provides security controls to limit and monitor the traffic between them. This would allow the business to get the required reports from the historian server without exposing the ОТ environment to unnecessary risks. Using a VPN, allowing IT traffic, or allowing PLCs to send data are less secure options that could compromise the ОТ environment. Verified References: https://www.comptia.org/blog/what-is-operational-technology https://partners.comptia.org/docs/default-source/resources/casp-content-guide

A wildcard certificate is a certificate that can be used for multiple subdomains of a domain, such as *.example.com. This would allow the inspection of the data without multiple certificate deployments, as one wildcard certificate can cover all the subdomains that will be separated out with subdomains. Including all available cipher suites may not help with inspecting the data without multiple certificate deployments, as cipher suites are used for negotiating encryption and authentication algorithms, not for verifying certificates. Using a third-party CA (certificate authority) may not help with inspecting the data without multiple certificate deployments, as a third-party CA is an entity that issues and validates certificates, not a type of certificate. Implementing certificate pinning may not help with inspecting the data without multiple certificate deployments, as certificate pinning is a technique that hardcodes the expected certificate or public key in the application code, not a type of certificate. Verified References:https://www.comptia.org/blog/what-is-a-wildcard-certificate https://partners.comptia.org/docs/default-source/resources/casp-content-guide

Moving the server to a cloud provider is the most cost-effective solution to avoid performance issues caused by too many connections during peak seasons, such as holidays. Moving the server to a cloud provider can provide scalability, elasticity, and availability for the web server, as it can adjust its resources and capacity according to the demand and traffic. Moving the server to a cloud provider can also reduce operational and maintenance costs, as the cloud provider can handle the infrastructure and security aspects. Changing the operating system may not help avoid performance issues, as it could introduce compatibility or functionality problems, and it may not address the resource or capacity limitations. Buying a new server and creating an active-active cluster may help avoid performance issues, but it may not be cost-effective, as it could involve hardware and software expenses, as well as complex configuration and management tasks. Upgrading the server with a new one may help avoid performance issues, but it may not be cost-effective, as it could involve hardware and software expenses, as well as migration and testing efforts. Verified References: https://www.comptia.org/blog/what-is-cloud-computing https://partners.comptia.org/docs/default-source/resources/casp-content-guide