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

To support email authenticity and enable analysis by a third-party platform, the protocols must verify the sender’s identity and provide metadata for inspection. According to the CompTIA SecurityX CAS-005 study guide (Domain 3: Cybersecurity Technology, 3.2):

DMARC (Domain-based Message Authentication, Reporting, and Conformance):DMARC builds on SPF and DKIM to enforce policies for email authenticity and provides reporting mechanisms to share authentication results with third parties for analysis.

DKIM (DomainKeys Identified Mail):DKIM adds a cryptographic signature to emails, allowing recipients to verify the sender’s domain and ensure the email’s integrity.

These two protocols are essential for authenticity and reporting.

Option C (TLS):TLS ensures encryption during transmission but does not address authenticity or reporting.

Option D (SPF):SPF verifies sender IP addresses but lacks reporting capabilities without DMARC.

Option E (DNSSEC):DNSSEC secures DNS queries but is not specific to email authenticity.

Option F (MX):MX records define mail servers, not authenticity or reporting.

The best way to prevent application-focused attacks for a platform-as-a-service solution with a web-based front end is to create Web Application Firewall (WAF) policies for relevant programming languages. Here's why:

Application-Focused Attack Prevention: WAFs are designed to protect web applications by filtering and monitoring HTTP traffic between a web application and the Internet. They help prevent attacks such as SQL injection, cross-site scripting (XSS), and other application-layer attacks.

Customizable Rules: WAF policies can be tailored to the specific programming languages and frameworks used by the web application, providing targeted protection based on known vulnerabilities and attack patterns.

Real-Time Protection: WAFs provide real-time protection, blocking malicious requests before they reach the application, thereby enhancing the security posture of the platform.

Based on the security policy that any publicly available server must be patched within 12 hours after a patch is released, the securityanalyst should patch Host 1 first. Here’s why:

Public Availability: Host 1 is externally available, making it accessible from the internet. Publicly available servers are at higher risk of being targeted by attackers, especially when a zero-day vulnerability is known.

Exposure to Threats: Host 1 has IIS installed and is publicly accessible, increasing its exposure to potential exploitation. Patching this host first reduces the risk of a successful attack.

Prioritization of Critical Assets: According to best practices, assets that are exposed to higher risks should be prioritized for patching to mitigate potential threats promptly.

RACI matrix(Responsible, Accountable, Consulted, Informed) is used for role mapping across the project lifecycle.

CMDB is a configuration inventory; ITIL is a framework. Recall trees are for disaster recovery/business continuity.

FromCAS-005, Domain 1: Security Governance and Compliance:

“The RACI matrix is essential in role assignment and accountability for software development and operational processes.”

Step by Step Explanation:

Understanding the Scenario: Theorganization is using customer-managed encryption keys in the cloud, which is more expensive than using the cloud provider's free managed keys. The CISO needs to find a way to reduce costs without significantly weakening the security posture.

Analyzing the Answer Choices:

A. Utilize an on-premises HSM to locally manage keys: While on-premises HSMs offer strong security, they introduce additional costs and complexity (procurement, maintenance, etc.). This option is unlikely to reduce costs compared to cloud-based key management.

B. Adjust the configuration for cloud provider keys on data that is classified as public: This is the most practical and cost-effective approach. Data classified as public doesn't require the same level of protection as sensitive data. Using the cloud provider's free managed keys for public data can significantly reduce costs without compromising security, as the data is intended to be publicly accessible anyway.

Automating compliance in cloudenvironments requires a tool that can enforce configurations, manage infrastructure as code, and align with industry standards (e.g., NIST, ISO). Let’s evaluate:

A. Jenkins:A CI/CD tool for automating software builds and deployments. It’s not designed for compliance enforcement or infrastructure management.

B. Python:A programming language that can be scripted for automation but lacks built-in compliance-focused features without significant custom development.

C. Ansible:An automation tool for configuration management, application deployment, and compliance enforcement. It uses playbooks to define desired states, making it ideal for automating compliance checks and remediation in cloud environments (e.g., AWS, Azure). CAS-005 emphasizes automation tools for security and compliance, and Ansible fits perfectly.

A Configuration Management Database (CMDB) provides the best foundation for identifying which specific assets are affected by a given vulnerability. A CMDB maintains detailed information about the IT environment, including hardware, software, configurations, and relationships between assets. This comprehensive view allows organizations to quickly identify and address vulnerabilities affecting specific assets.

The logs reviewed for the user indicate that access is being denied due to time-based access restrictions. These restrictions are commonly implemented to limit access to systems during specific hours to enhance security. If a user attempts to authenticate outside of the allowed time window, access will be denied. This measure helps prevent unauthorized access during non-business hours, reducing the risk of security incidents.

OWIN23 is running Windows 7, which is a legacy operating system. Many EDR solutions no longer provide full support for outdated operating systems like Windows 7, which has reached its end of life and is no longer receiving security updates from Microsoft. This makes such systems more vulnerable to infections and attacks, including remote access Trojans (RATs).

A. OWIN23 uses a legacy version of Windows that is not supported by the EDR: This is the most probable cause because the lack of support means that the EDR solution may not fully protect or monitor this system, making it an easy target for infections.

B. LN002 was not supported by the EDR solution and propagates the RAT: While LN002 is unmanaged, it is less likely to propagate the RAT to OWIN23 directly without an established vector.

C. The EDR has an unknown vulnerability that was exploited by the attacker: This is possible but less likely than the lack of support for an outdated OS.

D. OWIN29 spreads the malware through other hosts in the network: While this could happen, the status indicates OWIN29 is in a bypass mode, which might limit its interactions but does not directly explain the infection on OWIN23.

This scenario describes anenterprise VPN setup that requires machine authenticationbefore a user logs in. The best explanation for this requirement is that theVPN client selects the appropriate certificate automaticallybased on the key extension in the machine certificate.

Understanding the Key Extension Requirement:

PKI (Public Key Infrastructure)issues machine certificates that include specific key usages such asClient AuthenticationorIPSec IKE Intermediate.

Key usage extensionsdefine how a certificate can be used, ensuring that onlyvalid certificates are selected by the VPN client.

Why Option B is Correct:

The VPNautomaticallyselects the correct machine certificate with the appropriate key extension.

The process occurswithout user intervention, ensuring seamless VPN authentication before login.

Why Other Options Are Incorrect:

A (MFA requirement):Certificates used in this scenario are for machine authentication, not user MFA. MFA typically involves user credentials plus a second factor (like OTPs or biometrics), which isnot applicable here.

C (Wi-Fi connectivity before login):This refers topre-logon networking, which is a separate concept where devices authenticate to a Wi-Fi network before login, usually via 802.1X EAP-TLS. However, this question specifically mentions VPN authentication, not Wi-Fi authentication.

D (SSL VPN with certificates):While SSL VPNs do use certificates,this scenario involves machine certificates issued by an internal PKI, which are commonly used inIPSec VPNs, not SSL VPNs.

Excessive MFA push notifications can be a sign of an attempted push notification attack, where attackers repeatedly send MFA prompts hoping the user will eventually approve one by mistake. To mitigate this:

A. Provisioning FIDO2 devices: While FIDO2 devices offer strong authentication, they may not be practical for all users and do not directly address the issue of excessive push notifications.

B. Deploying a text message-based MFA: SMS-based MFA can still be vulnerable to similar spamming attacks and phishing.

C. Enabling OTP via email: Email-based OTPs add another layer of security but do not directly solve the issue of excessive notifications.

D. Configuring prompt-driven MFA: This option allows users to respond to prompts in a secure manner, often including features like time-limited approval windows, additional verification steps, or requiring specificactions to approve. This can help prevent users from accidentally approving malicious attempts.

Configuring prompt-driven MFA is the best solution to restrict unnecessary MFA notifications and improve security.

To enable code signing with an existing PKI, the first step is to configure the Certificate Authority (CA) to issue code signing certificates. Adding a new template with attributes specific to code signing (e.g., key usage for signing) allows the CA to support this requirement without disrupting existing operations.

Option A:Correct—templates define certificate types; this isthe foundational step.

Option B:Wildcard certificates are for domains, not code signing.

Option C:Recalculating root CA keys is unnecessary and risky unless compromised.

Option D:SAN (Subject Alternative Name) is for multi-domain certificates, irrelevant here.

The best solution is to implement authentication for API requests and apply appropriate rate limiting (C). Authentication ensures that only authorized customers or systems can access the API, while rate limiting helps prevent denial-of-service (DoS)-like conditions and cost inflation from excessive or malicious requests. This addresses both the security (unauthorized access) and cost issues (serverless billing based on execution).

Option A (digital certificates) is a strong control for authentication but may introduce unnecessary complexity and does not address rate abuse directly. Option B (rate limits with IP reputation checks) is useful but insufficient—malicious actors may rotate through new IPs not yet flagged. Option D (regional restrictions) might reduce some noise traffic but risks blocking legitimate global users and is not scalable for a modern cloud service.

CAS-005 highlights securing APIs with authentication, authorization, and throttling as best practices. Thus, the combined approach of API authentication plus rate limiting is the most comprehensive and effective solution.

The incident highlights gaps in visibility, monitoring, and log management that allowed unauthorized access to persist undetected. The most critical corrective actions are to extend log retention for all devices (B) and to ensure all devices are forwarding relevant logs to the SIEM (E). Together, these steps strengthen monitoring and incident detection capabilities by ensuring that sufficient telemetry is collected, stored, and available for correlation and investigation.

Disabling bulk user creation (A) may reduce misuse but does not directly address monitoring gaps. Daily review of the application allow list (C) is operationally impractical and does not provide the breadth of monitoring needed. Routine patching (D) is essential for security hygiene but is separate from monitoring improvements. Configuring firewall rules (F) may reduce traffic flows but does not ensure detection or visibility of unauthorized activity.

By prioritizing comprehensive log collection and ensuring adequate retention, the SOC can correlate anomalies across systems, detect malicious behavior earlier, and conduct forensic investigations effectively. This aligns with CAS-005 best practices for security operations and continuous monitoring in hybrid environments.

The code snippet exposes a hardcoded access token in a public repository. According to SecurityX CAS-005 secure coding best practices, the immediate action must be to revoke the exposed secret to prevent unauthorized access.

Removing the code from public view without revoking the token leaves the secret still usable by any attacker who has already seen or copied it.

SAST scanning would detect the issue but not mitigate it immediately.

Security awareness training is a long-term prevention measure but does not fix the immediate exposure.Revoking the secret first stops ongoing exploitation, after which the code can be removed, and preventative measures can be implemented.

Based on the provided authentication logs, we observe that User1's accountexperienced multiple failed login attempts within a very short time span (at 8:01:23 AM on 12/15). This pattern indicates a potential brute-force attack or an attempt to gain unauthorized access. Here’s a breakdown of why disabling User1's account is the appropriate first step:

Failed Login Attempts: The logs show that User1 had four consecutive failed login attempts:

VM01 at 8:01:23 AM

VM08 at 8:01:23 AM

VM01 at 8:01:23 AM

VM08 at 8:01:23 AM

Security Protocols and Best Practices: According to CompTIA Security+ guidelines, multiple failed login attempts within a short timeframe should trigger an immediate response to prevent further potential unauthorized access attempts. This typically involves temporarily disabling the account to stop ongoing brute-force attacks.

Account Lockout Policy: Implementing an account lockout policy is a standard practice to thwart brute-force attacks. Disabling User1's account will align with these best practices and prevent further failed attempts, which might lead to successful unauthorized access if not addressed.

Whencreating a threat model to identify vulnerabilities in an organization's infrastructure, prioritizing external-facing infrastructure with known exploited vulnerabilities is critical. Here’s why:

Exposure to Attack: External-facinginfrastructure is directly exposed to the internet, making it a primary target for attackers. Any vulnerabilities in this layer pose an immediate risk to the organization's security.

Known Exploited Vulnerabilities: Vulnerabilities that are already known and exploited in the wild are of higher concern because they are actively being used by attackers. Addressing these vulnerabilities reduces the risk of exploitation significantly.

Risk Mitigation: By prioritizing external-facing infrastructure with known exploited vulnerabilities, the organization can mitigate the most immediate and impactful threats, thereby improving overall security posture.

Code Snippet 1

Vulnerability 1: SQL injection

SQL injection is a type of attack that exploits a vulnerability in the code that interacts with a database. An attacker can inject malicious SQL commands into the input fields, such as username or password, and execute them on the database server. This can result in data theft, data corruption, or unauthorized access.

Fix 1: Perform input sanitization of the userid field.

Input sanitization is a technique that prevents SQL injection byvalidating and filtering the user input values before passing them to the database. The input sanitization should remove any special characters, such as quotes, semicolons, or dashes, that can alter the intended SQL query. Alternatively, the input sanitization can use a whitelist of allowed values and reject any other values.

Code Snippet 2

Vulnerability 2: Cross-site request forgery

Cross-site request forgery (CSRF) is a type of attack that exploits a vulnerability in the code that handles web requests. An attacker can trick a user into sending a malicious web request to a server that performs an action on behalf of the user, such as changing their password, transferring funds, or deleting data. This can result in unauthorized actions, data loss, or account compromise.

Fix 2: Implement anti-forgery tokens.

Anti-forgery tokens are techniques that prevent CSRF by adding a unique and secret value to each web request that is generated by the server and verified by the server before performing the action. The anti-forgery token should be different for each user and each session, and should not be predictable or reusable by an attacker. This way, only legitimate web requests from the user’s browser can be accepted by the server.

SecurityX CAS-005 network architecture objectives emphasize limiting exposure of vulnerable systems by using application-aware firewalls with strict rule sets.

This approach directly reduces the attack surface by allowing only approved application traffic to and from the vulnerable systems, mitigating risk until systems are patched or replaced.

EDR (A) enhances detection but doesn’t inherently reduce the exposed services.

Network segmentation in monitor mode (B) doesn’t block threats.

IDS (C) detects activity but does not block it.