CS0-003 CompTIA CyberSecurity Analyst CySA+ Certification Exam Free Practice Exam Questions (2026 Updated)

The correct answer is D because the remediation was successful technically, but it occurred during five business hours for a sales application. That means the company likely lost sales revenue because the application was unavailable or degraded during a business-critical period. The issue was not the patch itself; the issue was poor change scheduling and communication.

Exact supporting extract: the CySA+ All-in-One guide defines a maintenance window as “a scheduled time the system is taken offline or out of use so that patches or configuration changes can be made.” It also explains that emergency maintenance may require informing users that the resource is being taken offline, how long maintenance will take, and whether resource access will be affected.

The Sybex CySA+ Study Guide also supports this answer: “Changes have the potential to be disruptive to an organization,” so the timing of changes must be “carefully coordinated.” It adds that maintenance windows normally occur during evenings, weekends, or other periods when business activity is low.

The official CompTIA CS0-003 objectives place this under vulnerability management reporting and communication because they include action plans, patching, inhibitors to remediation, business process interruption, degrading functionality, and stakeholder identification and communication.

Why the other options are incorrect:

A is incorrect because this financial loss is not simply a normal unavoidable IT cost. It was caused by poor scheduling or communication around a business-critical sales application.

B is incorrect because the issue is not specifically that the CIO failed to notify the board. The scenario says the change advisory board informed leadership after the loss.

C is incorrect because a penetration test is not required before every patch or remediation activity. The issue was not whether the vulnerability existed; it was the business impact of the remediation timing.

D is correct because a properly planned and communicated maintenance window should reduce business impact by scheduling the work when the application is not heavily used.

Thepost-incident review processhelps an organization identify gaps in its response and security posture. Assigning different departmental groups ensures that flaws inspecific work areas (such as IT, HR, or legal teams)are identified and addressed​.

Option Bis incorrect because not all staff need exposure; the review focuses on relevant stakeholders.

Option Cis a part of the process, but the main goal is improvement, not just playbook verification.

Option D(cross-training) is a benefit but not the main objective.

Thus,A is the best answerbecause it focuses on identifyingflaws in specific areas of incident management.

SOAR (Security Orchestration, Automation, and Response) is the best option to help the analyst implement the recommendation, as it reflects the software solution that enables security teams to integrate and coordinate separate tools into streamlined threat response workflows and automate repetitive tasks. SOAR is a term coined by Gartner in 2015 to describe a technology that combines the functions of security incident response platforms, security orchestration and automation platforms, and threat intelligence platforms in one offering. SOAR solutions help security teams to collect inputs from various sources, such as EDR agents, firewalls, or SIEM systems, and perform analysis and triage using a combination of human and machine power. SOAR solutions also allow security teams to define and execute incident response procedures in a digital workflow format, using automation to perform low-level tasks or actions, such as blocking an IP address or quarantining a device. SOAR solutions can help security teams to improve efficiency, consistency, and scalability of their operations, as well as reduce mean time to detect (MTTD) and mean time to respond (MTTR) to threats. The other options are not as suitable as SOAR, as they do not match the description or purpose of the recommendation. SIEM (Security Information and Event Management) is a software solution that collects and analyzes data from various sources, such as logs, events, or alerts, and provides security monitoring, threat detection, and incident response capabilities. SIEM solutions can help security teams to gain visibility, correlation, and context of their security data, but they do not provide automation or orchestration features like SOAR solutions. SLA (Service Level Agreement) is a document that defines the expectations and responsibilities between a service provider and a customer, such as the quality, availability, or performance of the service. SLAs can help to manage customer expectations, formalize communication, and improve productivity and relationships, but they do not help to implement technical recommendations like SOAR solutions. IoC (Indicator of Compromise) is a piece of data or evidence that suggests a system or network has been compromised by a threat actor, such as an IP address, a file hash, or a registry key. IoCs can help to identify and analyze malicious activities or incidents, but they do not help to implement response actions like SOAR solutions.

The best recommendations to prevent an XSS vulnerability from being exploited are to implement a compensating control in the source code and to fix the vulnerability using a virtual patch at the WAF. A compensating control is a technique that mitigates the risk of a vulnerability by adding additional security measures, such as input validation, output encoding, or HTML sanitization. A virtual patch is a rule that blocks or modifies malicious requests or responses at the WAF level, without modifying the application code. These recommendations are effective, efficient, and less disruptive than the other options. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 4: Security Operations and Monitoring, page 156; Cross Site Scripting Prevention Cheat Sheet, Section: XSS Defense Philosophy.

The correct regular expression to match a GET request to this API endpoint is " https://10\.1\.2\.3/api\?id=\d+ " . This pattern checks for the specific URL with an id parameter that accepts integer values. The syntax \d+ matches one or more digits, which aligns with the requirement for a single integer argument. Other options either use incorrect syntax or do not accurately capture the expected URL format. Regular expressions are vital in filtering and identifying patterns in logs, as recommended by CompTIA Cybersecurity Analyst (CySA+) practices for threat hunting and log analysis.

Federation is a system of trust between two parties for the purpose of authenticating users and conveying information needed to authorize their access to resources. By using federation, a user can use one set of credentials to access multiple domains that trust each other.

The most likely attack that was performed is CSRF (Cross-Site Request Forgery). This is an attack that forces a user to execute unwanted actions on a web application in which they are currently authenticated1. If the user has several tabs open in the browser, one of them might contain a malicious link or form that sends a request to the web application to change the user’s password, email address, or other account settings. The web application will not be able to distinguish between the legitimate requests made by the user and the forged requests made by the attacker. As a result, the user will lose access to their account.

To prevent CSRF attacks, web applications should implement some form of anti-CSRF tokens or other mechanisms that validate the origin and integrity of the requests2. These tokens are unique and unpredictable values that are generated by the server and embedded in the forms or URLs that perform state-changing actions. The server will then verify that the token received from the client matches the token stored on the server before processing the request. This way, an attacker cannot forge a valid request without knowing the token value.

Some other possible attacks that are not relevant to this scenario are:

RFI (Remote File Inclusion) is an attack that allows an attacker to execute malicious code on a web server by including a remote file in a script. This attack does not affect the user’s browser or account settings.

LFI (Local File Inclusion) is an attack that allows an attacker to read or execute local files on a web server by manipulating the input parameters of a script. This attack does not affect the user’s browser or account settings.

XSS (Cross-Site Scripting) is an attack that injects malicious code into a web page that is then executed by the user’s browser. This attack can affect the user’s browser or account settings, but it requires the user to visit a compromised web page or click on a malicious link. It does not depend on having several tabs open in the browser.

 The first thing that must be done when starting an investigation is to secure the scene. Securing the scene involves isolating and protecting the area where the incident occurred, as well as any potential evidence or witnesses. Securing the scene can help prevent any tampering, contamination, or destruction of evidence, as well as any interference or obstruction of the investigation.

The first action that should be completed to remediate the findings is to perform proper sanitization on all fields. Sanitization is a process that involves validating, filtering, or encoding any user input or data before processing or storing it on a system or application. Sanitization can help prevent various types of attacks, such as cross-site scripting (XSS), SQL injection, or command injection, that exploit unsanitized input or data to execute malicious scripts, commands, or queries on a system or application. Performing proper sanitization on all fields can help address the most critical and common vulnerability found during the vulnerability assessment, which is XSS.

The correct answer is B because a legal hold requires the organization to preserve potentially relevant information. The first practical step is to notify the departments, custodians, IT staff, and records personnel who may control or possess relevant emails so they do not delete, alter, or overwrite them.

Exact supporting extract: the Secbay CySA+ guide defines legal hold as a process used to preserve relevant information associated with legal proceedings, investigations, or disputes. It states that once a legal hold is in effect, it is crucial to communicate it to relevant personnel who may have custody or control over the information, including IT staff, records management personnel, and employees with pertinent data.

The Sybex CySA+ Study Guide also states that legal holds require organizations to preserve all potentially relevant data and information related to pending or active litigation. It specifically notes that legal holds may involve data such as logs, email, or transactional information that would otherwise be destroyed under normal retention procedures.

Why the other options are incorrect:

A is incorrect because disclosing the request to unrelated vendors could create confidentiality and legal issues.

C is incorrect because chain of custody is important when evidence is collected and transferred, but the first legal-hold step is preservation notification.

D is incorrect because producing mailbox copies to the attorney is premature. The organization must first preserve the relevant data and follow legal/eDiscovery procedures.

The correct answer is D. Diamond Model of Intrusion Analysis. The Diamond Model is used to analyze intrusions by examining the relationships between the adversary, capability, infrastructure, and victim. This makes it useful for understanding how an adversary operates, including their tools, infrastructure, tactics, techniques, and procedures.

Exact supporting extract: the Secbay CySA+ guide explains that the Diamond Model highlights four components: adversary, capabilities, infrastructure, and victims. It further states that the adversary element focuses on understanding the adversary’s capabilities, intentions, motivations, tactics, techniques, procedures, and objectives.

The All-in-One CySA+ guide also explains that the Diamond Model provides a structured approach to analyzing cyberattacks and that its four components provide a comprehensive view of an intrusion, allowing analysts to identify attackers’ goals, motivations, tactics, techniques, and infrastructure.

Why the other options are incorrect:

A. OWASP is focused mainly on web application security testing, not adversary method analysis.

B. Penetration Test Framework is used to structure penetration testing activities, not to model adversary intrusion behavior.

C. OSSTMM is a security testing methodology for evaluating systems, networks, and applications.

D. Diamond Model of Intrusion Analysis is best because it is specifically designed to analyze adversary behavior and intrusion relationships.

When prioritizing vulnerabilities, analysts consider theCVSS score, whether the system isinternet-facing, and ifsensitive datais involved. The primary goal is to mitigate the mostexploitableandimpactfulrisks first.

Let ' s break down the key components:

Attack Vector (AV): Whether the attack can be launched remotely (N = Network) or locally (L = Local).

Attack Complexity (AC): The difficulty of executing the attack (L = Low, H = High).

Privileges Required (PR): The level of access needed for exploitation (N = None, L = Low, H = High).

User Interaction (UI): Whether user interaction is required for the attack (N = No, R = Required).

Scope (S): Whether the attack affects other systems (C = Changed, U = Unchanged).

Confidentiality (C), Integrity (I), Availability (A): The impact level (H = High, L = Low, N = None).

Evaluating Each System:

System 1 (CVSS: AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H)

Internet-facing✅

No sensitive data❌

High confidentiality and availability impact✅

Moderate risk due to requiring low privileges

System 2 (CVSS: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H)

Not internet-facing❌

No sensitive data❌

Lower priority since it’s local-only

System 3 (CVSS: AV:P/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L)

Internet-facing✅

Contains sensitive data✅

But very low likelihood of exploit (requires physical access, high privileges, user interaction)

Lower priority due to high attack complexity

System 4 (CVSS: AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:H)

Internet-facing✅

No sensitive data❌

No privileges required for exploitation✅

High impact on confidentiality and availability✅

Most critical due to remote exploitability and system-wide scope

System 5 (CVSS: AV:L/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N)

Internet-facing✅

Contains sensitive data✅

But requires high privileges, high attack complexity, and user interaction

Lower priority than System 4

System 6 (CVSS: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H)

Not internet-facing❌

No sensitive data❌

Same as System 2 (low priority due to being local-only)

Final Decision: Patch System 4 First

System 4 is themost criticalbecause:

It isinternet-facing(higher exposure).

It has ahigh CVSS score.

Itrequires no privileges(easy to exploit).

It hassystem-wide scope impact(can affect other systems).

Thus, it should bepatched firstto minimize security risks.

Proprietary systems are systems that are owned and controlled by a specific vendor or manufacturer, and that use proprietary standards or protocols that are not compatible with other systems. Proprietary systems can pose a challenge for vulnerability management, as they may not allow users to access or modify their configuration, update their software, or patch their vulnerabilities. In this case, two of the critical systems cannot be upgraded due to a vendor appliance that the company does not have access to. This indicates that these systems and associated vulnerabilities are examples of proprietary systems as inhibitors to remediation

 The script uses PowerShell syntax, such as cmdlets, parameters, variables, and comments. PowerShell is a scripting language that can be used to automate tasks and manage systems.

Agent-based scanning is a method that involves installing software agents on the target systems or networks that can perform local scans and report the results to a central server or console. Agent-based scanning can reduce the access to systems, as the agents do not require any credentials or permissions to scan the local system or network. Agent-based scanning can also provide the most accurate vulnerability scan results, as the agents can scan continuously or on-demand, regardless of the system or network status or location.

OpenVAS is an open-source tool that performs comprehensive vulnerability scanning and assessment on the network. It can generate reports and evidence of the scan results, which can be used for auditingpurposes. References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 5, page 199; CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 5, page 207.

The most likely cause of the issue where an ICS (Industrial Control System) could not be updated due to hardware versioning incompatibility is a legacy system. Legacy systems often have outdated hardware and software that may not be compatible with modern updates and patches. This can pose significant challenges in maintaining security and operational efficiency.

Dictionary attacks involve an attacker attempting to guess passwords by using a list of common passwords. Implementing a lockout policy is effective because it limits the number of login attempts, thereby hindering the attacker ' s ability to repeatedly attempt different passwords. Lockout policies are standard in cybersecurity practices to prevent brute-force and dictionary attacks by temporarilydisabling an account after a certain number of failed login attempts. According to CompTIA Security+ standards, password complexity (option B) and multifactor authentication (option A) are helpful but are not as immediately effective in directly preventing repeated attempts as a lockout policy.

The analyst should look at p4wnp1_aloa.lan (192.168.86.56) first, as this is the most suspicious device on the network. P4wnP1 ALOA is a tool that can be used to create a malicious USB device that can perform various attacks, such as keystroke injection, network sniffing, man-in-the-middle, or backdoor creation. The presence of a device with this name on the network could indicate that an attacker has plugged in a malicious USB device to a system and gained access to the network. Official References: https://github.com/mame82/P4wnP1_aloa