CompTIA  CS0-003 Exam Dumps & Practice Test Questions

Question 1:

A newly discovered zero-day vulnerability is under active exploitation. It does not require any user input or elevated access privileges, severely compromises both confidentiality and integrity, but leaves system availability unaffected.

Which of the following CVSS vector strings best represents this threat?

A. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:K/A:L
B. CVSS:3.1/AV:K/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L
C. CVSS:3.1/AV:N/AC:L/PR:N/UI:H/S:U/C:L/I:N/A:H
D. CVSS:3.1/AV:L/AC:L/PR:R/UI:R/S:U/C:H/I:L/A:H

Answer: A

Explanation:

When evaluating the severity of a zero-day exploit, especially one actively being used in attacks, the Common Vulnerability Scoring System (CVSS) helps quantify its characteristics. In this scenario, the attack has the following properties: it requires no user involvement, needs no elevated access rights, and impacts confidentiality and integrity severely, while leaving availability largely unaffected.

Let’s decode the vector for option A, and why it matches the scenario perfectly:

• AV:N (Attack Vector: Network): The attack is conducted remotely, over the network, without physical or local access. This matches the stated characteristic that the attack doesn’t need user interaction or device access.

• AC:L (Attack Complexity: Low): This indicates minimal complexity is needed to exploit the vulnerability—ideal for attackers and consistent with an easily exploitable zero-day.

• PR:N (Privileges Required: None): No admin rights or elevated permissions are necessary, reinforcing how easily the attack can be carried out.

• UI:N (User Interaction: None): The exploit is successful without the need for the victim to click, open, or engage—critical for a zero-day classification.

• S:U (Scope: Unchanged): The effects remain within the same security boundary. The exploit affects only the component it targets.

• C:H (Confidentiality Impact: High): The attacker gains unauthorized access to sensitive data—indicating a serious breach.

• I:K (Integrity Impact: Unknown): There’s a significant risk to data integrity, but the exact extent might still be under investigation, as is often the case with zero-days.

• A:L (Availability Impact: Low): Availability is minimally affected, consistent with the stated scenario.

The other options either involve elevated privileges (B, D), user interaction (C, D), or do not align with the zero-day’s minimal exploitation conditions.

Therefore, option A precisely captures the technical details and risk profile of the described zero-day exploit using the CVSS 3.1 metrics.

Question 2:

An organization is focused on safeguarding Personally Identifiable Information (PII) and wants to prevent it from being sent or accessed outside the company’s network boundaries.

Which of the following tools is best suited to enforce this objective?

A. PAM
B. IDS
C. PKI
D. DLP

Answer: D

Explanation:

The primary objective here is to prevent sensitive data, particularly PII, from leaving the organization—either intentionally or accidentally. To accomplish this, the best-suited technology is Data Loss Prevention (DLP).

DLP is specifically designed to monitor, detect, and stop sensitive data from being exfiltrated, exposed, or misused. It uses pattern recognition, keyword matching, file tagging, and policy enforcement to analyze data in transit (across email, cloud services, etc.), at rest (on storage), and in use (during file transfers or clipboard actions).

For example, if an employee tries to send a spreadsheet containing Social Security Numbers via email, DLP can automatically block that action, encrypt the file, or alert administrators. DLP also integrates with compliance frameworks (like GDPR, HIPAA, or PCI-DSS), ensuring sensitive information like health records or financial data is not mishandled.

Now let’s consider why the other tools aren’t suitable:

• A. PAM (Privileged Access Management): PAM manages elevated access accounts (like system administrators), ensuring only authorized personnel perform critical functions. It helps reduce insider threats but does not prevent general PII from leaving the network. Its scope is access control, not content control.

• B. IDS (Intrusion Detection System): IDS tools are designed to detect anomalies and unauthorized behavior within a network. While useful for spotting threats or breaches, IDS tools don’t actively prevent data loss. They also do not monitor data payloads to identify PII leakage.

• C. PKI (Public Key Infrastructure): PKI is about securing data through encryption and digital certificates. While it protects data in transit, it doesn't stop a user from sending sensitive data to unauthorized parties. It ensures privacy during transfer but lacks enforcement of data sharing policies.

In summary, DLP is the only solution among the options that directly tackles the prevention of unauthorized transmission or access of PII, making it the most appropriate choice for the scenario presented.

Question 3:

During a recent vulnerability scan of a company’s website, a report was generated highlighting a security issue related to iframe embedding. 

Based on this information, which recommendation should the security analyst make to improve the site’s defense?

A. Set an HttpOnly flag to force communication by HTTPS
B. Block requests without an X-Frame-Options header
C. Configure an Access-Control-Allow-Origin header to authorized domains
D. Disable the cross-origin resource sharing header

Correct Answer: B

Explanation:

The most suitable recommendation in this scenario is to block requests that do not include an X-Frame-Options header. This header plays a key role in defending websites against clickjacking attacks, where malicious actors trick users into clicking on hidden content or links embedded in iframes. If an attacker embeds the vulnerable website into their own site using an invisible iframe, they can manipulate users into executing unintended actions, such as approving a transaction or changing account settings.

Implementing the X-Frame-Options header with values like DENY or SAMEORIGIN restricts how the site can be framed by other domains. DENY prevents all framing, while SAMEORIGIN allows framing only from the same domain. This helps eliminate the possibility of the site being hijacked via an iframe, making it a critical part of secure web application configurations.

Let’s examine why the other options don’t effectively address the issue:

• A (HttpOnly flag): This flag is intended to protect cookies from being accessed via JavaScript, offering protection against cross-site scripting (XSS), not clickjacking. It also doesn’t enforce HTTPS as stated in the option.

• C (Access-Control-Allow-Origin): This header deals with CORS (Cross-Origin Resource Sharing), controlling access from different domains, which is unrelated to iframe security.

• D (Disabling CORS headers): Completely disabling CORS may interfere with legitimate application functionality and doesn’t directly mitigate the risk highlighted in the vulnerability report.

Ultimately, to directly counter the identified vulnerability and prevent malicious embedding of the web content, setting the X-Frame-Options header is the most relevant and effective defense strategy.

Question 4:

When preparing a vulnerability scan report for stakeholders, which two elements should definitely be included to support effective risk management and remediation efforts?

A. Lessons learned
B. Service-level agreement
C. Playbook
D. Affected hosts
E. Risk score
F. Education plan

Correct Answers: D, E

Explanation:

An effective vulnerability scan report should prioritize actionable insights that help the organization understand what systems are at risk and how critical those risks are. Therefore, including both the affected hosts and the risk score is essential.

• D (Affected hosts): This refers to a list of the systems—such as servers, endpoints, or network devices—that are impacted by vulnerabilities. Including IP addresses, hostnames, or asset tags provides clarity about where immediate remediation is needed. Without this information, the report lacks direction, making it difficult for technical teams to prioritize fixes or isolate compromised systems.

• E (Risk score): The risk score assigns a quantitative or qualitative severity level to each vulnerability. These scores help prioritize remediation based on how likely the vulnerabilities are to be exploited and what the consequences would be if they were. Tools often use scoring frameworks like CVSS (Common Vulnerability Scoring System) to assign these values, providing a standardized way to rank issues by severity.

Now, why are the other options less appropriate?

• A (Lessons learned): While valuable in post-incident reviews or long-term improvement cycles, this isn’t typically part of a vulnerability scan report, which is focused on current findings.

• B (Service-level agreement): SLAs are contractual obligations regarding service availability or response time. They aren’t relevant to listing or analyzing technical vulnerabilities.

• C (Playbook): A playbook outlines incident response steps but doesn’t belong in a vulnerability scan report. It’s more useful during a security incident or as part of a broader response plan.

• F (Education plan): Although security training is important, a vulnerability report isn’t the right place for outlining education initiatives. Those belong in awareness campaigns or training strategies.

To sum up, affected hosts and risk scores are vital to translating scan data into practical remediation strategies.

Question 5:

A company executive learned that threat actors typically start exploiting newly disclosed vulnerabilities about 45 days after a patch becomes available. 

Which of the following strategies would most effectively help protect the organization against such attacks?

A. A mean time to remediate of 30 days
B. A mean time to detect of 45 days
C. A mean time to respond of 15 days
D. Third-party application testing

Correct Answer: A

Explanation:

To stay ahead of attackers who begin exploiting new vulnerabilities roughly 45 days after patches are released, the organization must act faster to apply patches and remediate weaknesses. The best proactive measure is to maintain a mean time to remediate (MTTR) of 30 days, giving the company a 15-day safety buffer before exploitation is likely.

The MTTR is the average time taken to fix a vulnerability from the moment it is identified. Setting an MTTR of 30 days ensures vulnerabilities are addressed well before the window of exploitation typically opens. This not only strengthens security posture but also aligns with industry best practices for vulnerability management, reducing the organization’s exposure to threats.

Let’s examine the alternatives:

• B (Mean time to detect of 45 days): Detection after 45 days means the vulnerability has already been exposed for too long, possibly leaving the system open to attack. The goal should be early detection, not meeting the exploit timeline.

• C (Mean time to respond of 15 days): While fast response to incidents is important, it happens after a breach or attack occurs. Preventing the exploit in the first place—via quick remediation—is more effective in this context.

• D (Third-party application testing): Testing third-party applications is necessary for assessing risks from external software, but it doesn’t directly address the patching timeline of known vulnerabilities affecting the organization's systems.

In summary, maintaining an MTTR of 30 days provides a strong defense by reducing the time vulnerabilities remain unpatched, significantly lowering the risk of exploitation before attackers act.

Question 6:

A cybersecurity analyst who recently joined the team needs to identify the scripting language used in a production script to evaluate its potential malicious nature. 

Based on the characteristics of the code, which of the following scripting languages is most likely used?

A. PowerShell
B. Python
C. Bash
D. JavaScript

Correct Answer: A

Explanation:

When trying to determine the nature of a script, especially one that could be used in a malicious context within a Windows environment, it's important to look at the language’s syntax, its system-level capabilities, and how integrated it is with the operating system. PowerShell is a scripting language developed by Microsoft and is widely used for task automation and configuration management in Windows. Because of its deep ties to the Windows OS, it is also commonly leveraged in cyberattacks for lateral movement, privilege escalation, and data exfiltration.

Scripts written in PowerShell tend to exhibit some easily identifiable features. These include the use of cmdlets, which are specialized, built-in commands like Get-Process, Set-ExecutionPolicy, and New-Object. These cmdlets often follow a verb-noun naming pattern, which is unique to PowerShell. Additionally, PowerShell utilizes pipelines, allowing the output of one command to be passed as input into another using the pipe symbol (|). This chaining of operations is common in system scripts that automate administrative tasks.

Another key element of PowerShell is its use of objects. Unlike traditional scripting languages that typically handle output as plain text, PowerShell works with structured objects. This makes data manipulation and integration with system APIs much more seamless and powerful, allowing scripts to manage users, processes, services, and registry entries with ease.

In comparison, Ruby and Python are both general-purpose programming languages with distinct syntaxes. Ruby uses keywords like def and has blocks defined with end, while Python is known for its indentation-based syntax and the use of colons. Neither typically uses cmdlets or is natively designed to manage Windows system components in the same way PowerShell does.

Shell scripts are more common in Unix-like environments. They use tools like echo, ls, and grep, and do not feature PowerShell's unique object-oriented approach or verb-noun cmdlets.

Given these distinguishing traits, and assuming the script in question uses cmdlets, pipelines, and object manipulation, the scripting language is almost certainly PowerShell.

Question 7:

A company has reported that employee accounts were recently compromised. Users are also noticing that access to the internal portal sometimes defaults to HTTP, while other times it works via HTTPS. 

What is the most probable explanation for this behavior?

A. The portal’s SSL/TLS certificate has expired
B. The website lacks an enforced redirect from HTTP to HTTPS
C. Users’ browsers do not support HTTPS
D. The internal portal uses a self-signed certificate

Correct Answer: B

Explanation:

In situations where users experience inconsistent behavior between HTTP (unencrypted, port 80) and HTTPS (encrypted, port 443), and especially when that is accompanied by user account compromises, the scenario often suggests an on-path attack. Previously known as a man-in-the-middle (MITM) attack, an on-path attack involves an unauthorized actor intercepting or manipulating communications between users and a legitimate service. The attacker may either passively eavesdrop or actively alter the traffic, such as downgrading encrypted HTTPS connections to unencrypted HTTP.

In this case, the portal should ideally always force users to connect via HTTPS. If it sometimes allows HTTP connections or redirects users to HTTP, this may indicate an attacker is intentionally weakening the connection security. This can be done through techniques such as SSL stripping, where the attacker intercepts the initial request and removes HTTPS enforcement before relaying the request to the user over HTTP.

Option A, which refers to SSL certificate issues, is unlikely to cause fluctuating access between HTTP and HTTPS. If there were an issue with the SSL certificate, users would likely encounter persistent errors when attempting to access the HTTPS site, such as browser warnings or a complete inability to load the page.

Option C, which suggests that the server is redirecting traffic due to an overload, is also unlikely. Web servers under high load might delay or refuse connections, but they don’t typically redirect secure connections to insecure ones. Security policies in modern infrastructures are specifically configured to avoid such fallbacks.

Option D, referencing a BGP error, is more network infrastructure-focused and would impact broader routing or availability issues. It does not typically manifest as HTTP vs. HTTPS behavior on a specific internal portal.

Given the evidence and the presence of both account compromises and inconsistent connection protocols, the most plausible explanation is an internal actor executing an on-path attack, potentially rerouting or intercepting traffic to downgrade connections to HTTP for easier credential theft or session hijacking.

Question 8

Based on the company’s vulnerability management policy, which vulnerability should be addressed first?

The policy highlights the following:

• Use CVSSv3.1 Base Score metrics (Exploitability and Impact) to guide prioritization.

• When forced to choose, confidentiality takes precedence over availability.

• Vulnerabilities in externally accessible systems are prioritized over internal ones.

A. THOR.HAMMER: CVSS indicates a high impact on availability only; system is internal.
B. CAP.SHIELD: CVSS reveals a high confidentiality impact; system is external.
C. LOKI.DAGGER: High availability impact; system is external.
D. THANOS.GAUNTLET: High confidentiality impact; system is internal.

Correct Answer: B

Explanation:

The company’s security policy provides three critical prioritization criteria: CVSSv3.1 base metrics (exploitability and impact), a preference for confidentiality over availability, and a prioritization of external over internal systems.

Let's break down each option:

• Option A (THOR.HAMMER) affects an internal system and impacts only availability (A:H), with no effect on confidentiality or integrity. Since it's internal and does not impact confidentiality, it ranks low.

• Option B (CAP.SHIELD) impacts confidentiality (C:H) and runs on an external system. This aligns perfectly with two of the three policy priorities: it affects data confidentiality and is publicly exposed. This makes it the highest priority.

• Option C (LOKI.DAGGER), while also external, only impacts availability (A:H). Given the policy prioritizes confidentiality above availability, this is less urgent than CAP.SHIELD.

• Option D (THANOS.GAUNTLET) has a high confidentiality impact but is on an internal system. Though confidentiality is important, external systems still take precedence in exposure risk.

Considering all policy factors—impact on confidentiality, system exposure, and CVSS metrics—CAP.SHIELD (Option B) is the most critical and should be patched first.

Question 9

Which strategy best ensures that critical services remain functional after a major incident?

A. Business continuity plan
B. Vulnerability management plan
C. Disaster recovery plan
D. Asset management plan

Correct Answer: C

Explanation:

When it comes to maintaining access to mission-critical services after an incident such as a cyberattack, system failure, or natural disaster, the Disaster Recovery Plan (DRP) is the most targeted and effective strategy.

A DRP focuses specifically on how to recover IT services and infrastructure in the aftermath of a disruption. It includes well-documented procedures and contingency arrangements such as:

• Backup and Restore Processes: Ensures vital data is regularly backed up and can be quickly restored.

• Alternative Resources: Provides options like cloud failovers, secondary data centers, or backup servers to bring systems online quickly.

• Recovery Time Objectives (RTO) and Recovery Point Objectives (RPO): These metrics help define acceptable downtime and data loss, ensuring clarity and speed during recovery.

• Clear Communication Channels: Ensures IT teams, executives, and stakeholders remain informed throughout the recovery process.

Here’s why other plans don’t meet the criteria as well:

• A. Business Continuity Plan (BCP): While broader in scope and valuable for maintaining overall operations, it does not delve as deeply into IT restoration as the DRP does.

• B. Vulnerability Management Plan: This is proactive, aimed at reducing security threats before incidents occur. However, it doesn’t offer post-incident recovery guidance.

• D. Asset Management Plan: Focuses on inventory and lifecycle tracking of IT assets. It doesn’t ensure recovery of services or system continuity.

Only a well-structured Disaster Recovery Plan (C) guarantees a technical pathway to restoring mission-critical services after an unexpected disruption.

Question 10

To combat shadow IT and reduce associated risks from unapproved cloud apps, which solution would be most effective?

A. Deploy a CASB with policy enforcement
B. Implement MFA with strict policies
C. Use an API gateway
D. Enable SSO for cloud apps

Correct Answer: A

Explanation:

Shadow IT refers to the use of unauthorized or unapproved cloud services by employees, often without the knowledge or consent of the IT department. This practice increases security risks such as data leaks, compliance failures, and lack of visibility. The best way to manage this risk is by deploying a Cloud Access Security Broker (CASB) with strong policy enforcement capabilities.

A CASB acts as a gatekeeper between users and cloud services. It allows the organization to:

• Gain Visibility: Identify and catalog all cloud apps accessed by users, even those not officially approved.

• Control Usage: Apply granular policies like blocking risky apps, enforcing encryption, or requiring DLP (data loss prevention) checks.

• Ensure Compliance: Maintain regulatory requirements by auditing cloud activity and securing sensitive data.

• Mitigate Risk: Identify risky behavior and automatically respond through alerts or access restrictions.

Why the other options are less effective:

• B. MFA (Multi-Factor Authentication): While MFA increases access security, it doesn't detect or control use of unauthorized apps, meaning it doesn’t reduce shadow IT.

• C. API Gateway: This tool controls traffic between backend services and applications but doesn’t provide visibility or control over unsanctioned cloud app usage.

• D. SSO (Single Sign-On): Makes it easier for users to access authorized apps, but it doesn’t prevent or monitor the use of unapproved services.

By integrating CASB technology, the organization can monitor, manage, and control cloud usage across the enterprise, making Option A the most suitable choice for mitigating the dangers of shadow IT.