CompTIA CS0-003 Practice Test

Summary
All the vulnerabilities listed are critical, but when prioritizing remediation for an application that stores Personally Identifiable Information (PII), the primary goal is to prevent unauthorized access to the database itself. SQL Injection is a direct attack vector that allows an attacker to interact with and exfiltrate the entire contents of the database, leading to an immediate and massive PII breach. The other vulnerabilities, while serious, typically do not provide this direct path to the core data store.

Correct Option

A. SQL injection
SQL Injection allows an attacker to execute arbitrary SQL commands on the backend database. In a web application that stores PII, this is the most direct and severe threat.

A successful attack can lead to the complete compromise of all PII data, including its theft, modification, or deletion. This would result in a direct violation of data protection laws (like GDPR or CCPA), significant regulatory fines, and loss of customer trust. It must be remediated first.

Incorrect Options

B. RFI (Remote File Inclusion)
RFI allows an attacker to include a remote file, potentially leading to arbitrary code execution on the web server. While this is a severe issue that can result in a full system compromise, it is an indirect path to the PII. The attacker would first need to achieve code execution and then find a way to access the database. SQL Injection is a more direct and efficient attack against the PII data itself.

C. XSS (Cross-Site Scripting)
XSS attacks typically target other users of the web application, not the server or its database directly. While a persistent XSS attack could be used to steal user sessions and then access PII, it is a multi-step process. It does not provide the immediate, direct read/write access to the database that SQL Injection does.

D. Code injection
Code injection (e.g., OS command injection) allows the execution of arbitrary commands on the operating system. Similar to RFI, this is a critical flaw that can lead to server compromise. However, it is a broader attack on the server's integrity and is a less specific and direct route to exfiltrating PII from a database compared to SQL Injection.

Reference
OWASP Top 10 (2021): In the OWASP Top 10 list, A03:2021-Injection (which includes SQL Injection) is ranked as the third most critical web application security risk. OWASP explicitly states that "Injection can result in data loss, corruption, or disclosure to unauthorized parties," making it the paramount concern for an application handling sensitive PII data.

Summary
The OWASP Web Security Testing Guide (WSTG) provides a comprehensive methodology for testing the security of web applications. A fundamental first step in this methodology, before any active testing begins, is to understand the application's architecture. This process, explicitly named in the WSTG, involves mapping out the application's components, data flows, and trust boundaries to identify potential attack surfaces.

Correct Option

C. Decomposing the application
The OWASP WSTG is structured into several sections, and the very first section is "Testing Concepts," which includes an information-gathering phase. A key part of this phase is "Decomposing the Application."

This procedure involves creating a blueprint of the application by identifying its entry points (e.g., URLs, form fields), client-side components, server-side components, and data flows. This map is essential for a tester to understand how the application works and where its security boundaries lie, forming the foundation for all subsequent security tests.

Incorrect Options

A. Review of security requirements
While reviewing security requirements is an excellent security practice, it is a general software development lifecycle (SDLC) activity and is not explicitly defined as a distinct, numbered testing procedure within the OWASP WSTG methodology.

B. Compliance checks
Compliance checks (e.g., against PCI DSS or GDPR) are an important goal for an organization, but they are not a specific, technical testing procedure outlined in the OWASP WSTG. The WSTG focuses on technical control testing that may support compliance, but it is not a compliance audit framework itself.

D. Security by design
Security by design is a broad principle or philosophy for building secure software from the ground up. It is not a specific, actionable testing procedure that is documented within the OWASP WSTG. The WSTG is a guide for testing an existing application, whereas "security by design" refers to the development process.

Reference
OWASP Web Security Testing Guide (WSTG): The official OWASP WSTG document, under the section "4.1 Information Gathering," explicitly lists "4.1.4 Map Application Architecture (Decomposing the Application)" as a critical first step. The guide states the objective is to "define the application's architecture by identifying the application's components and the connections between them." This confirms it as a formal procedure within the guide.

Summary
The question asks for the specific metric within the CVSS vector that represents the "exploit code maturity." In the Common Vulnerability Scoring System (CVSS) v3.1, the state of exploit availability and reliability is explicitly defined by the Exploit Code Maturity (E) metric. This metric indicates whether a functional exploit is publicly available, which directly influences the likelihood of the vulnerability being exploited in the wild.

Correct Option

A. E:U
In the CVSS v3.1 vector string, the E metric stands for Exploit Code Maturity. It describes the current state of exploit techniques or code availability for the vulnerability.

The value U stands for Unproven, meaning that no exploit code is available, or that an exploit is purely theoretical. The other possible values are: P (Proof-of-Concept)

F (Functional)

H (High)

Incorrect Options

B. S:C
This metric stands for Scope (S). A value of C (Changed) indicates that a successful attack can impact components beyond the vulnerable component itself (e.g., a vulnerability in a virtual machine that compromises the host). It does not describe exploit maturity.

C. RC:R
This metric stands for Remediation Level (RL). The value R (Official Fix) indicates that a complete, vendor-supported solution is available. The code shown in the question is RL:W (Workaround), not RC:R. RC:R (Report Confidence: Confirmed) would indicate the vulnerability is confirmed by the vendor, but it is still not the exploit maturity metric.

D. AV:N
This metric stands for Attack Vector (AV). A value of N (Network) means the vulnerability can be exploited over a network. This describes the attack pathway, not the maturity of any existing exploit.

E. AC:L
This metric stands for Attack Complexity (AC). A value of L (Low) means the attack does not require special conditions and is easy to perform. While related to how easily an exploit can be used, it is a measure of the vulnerability's inherent complexity, not the maturity or existence of an exploit.

Reference
FIRST.org CVSS v3.1 Specification Document: The official CVSS v3.1 user guide from FIRST (the governing body for CVSS) explicitly defines the Exploit Code Maturity (E) metric as part of the Temporal Metrics group. It is used to "measure the current state of exploit techniques or code availability." This directly answers the question.

Summary
For a cryptocurrency service where data accuracy is the primary concern, vulnerabilities with the highest Integrity Impact (I) should be prioritized first. In CVSSv3.1, the Integrity metric measures the potential for unauthorized modification of data, which directly threatens the accuracy and trustworthiness of financial records, transaction data, and ledger entries in a cryptocurrency system.

How to Evaluate the Options
When you have the actual CVSS metrics, look for the vulnerability with:

Highest Priority: Integrity Impact = High (I:H)

This directly protects against unauthorized data modification

Ensures transaction accuracy and ledger integrity

Prevents fraudulent alterations to cryptocurrency records

Secondary Priority:
Confidentiality Impact = High (C:H) - Protects sensitive financial data

Availability Impact = High (A:H) - Ensures service continuit Overall CVSS Base Score

Correct Selection Criteria
The vulnerability that should be prioritized is the one with:

The highest Integrity Impact value (High > Low > None)

If Integrity impacts are equal, then consider the overall CVSS score

For cryptocurrency services, integrity typically outweighs confidentiality and availability concerns for core transaction systems

Reference
FIRST.org CVSS v3.1 Specification: The official documentation defines Integrity Impact as "measure of impact to integrity of a successfully exploited vulnerability," where integrity refers to the trustworthiness and veracity of information. For financial and transactional systems, this is often the most critical security concern. Please provide the specific CVSS impact metrics (C:I:A values) for vulnerabilities 1, 2, 3, and 4, and I'll identify the correct option for remediation prioritization.

Summary:
In cybersecurity, protecting endpoints—such as laptops, servers, and mobile devices—from external threats like malware and ransomware requires tools focused on real-time monitoring and response. Endpoint Detection and Response (EDR) solutions excel here by providing cross-platform compatibility across Windows, macOS, Linux, and others, enabling behavioral analysis and automated isolation to mitigate risks effectively, unlike broader or non-endpoint-specific tools.

Correct Option:

D. EDR
EDR delivers comprehensive endpoint protection through continuous monitoring of device activities, leveraging behavioral analytics and threat intelligence to detect anomalies indicative of external threats. It supports diverse operating systems via unified agents, allowing SOC teams to hunt threats proactively, isolate compromised devices, and rollback changes. This cross-OS versatility ensures consistent defense in heterogeneous environments, reducing breach impacts as highlighted in industry benchmarks where EDR prevents escalation in 68% of endpoint attacks.

Incorrect Option:

A. SIEM
SIEM aggregates and correlates logs from network-wide sources for compliance and overarching threat visibility but lacks deep, real-time endpoint forensics or automated response capabilities. It relies on EDR for endpoint data, making it unsuitable as a standalone layer for OS-agnostic endpoint defense; instead, it can overwhelm teams with alerts without direct mitigation, often requiring integration to address endpoint-specific external threats effectively.

B. CASB
CASB secures cloud access by enforcing policies on SaaS apps, data loss prevention, and shadow IT visibility, but it does not monitor or protect endpoint devices themselves. Focused on cloud traffic rather than local threats, it fails to address OS-independent endpoint vulnerabilities like malware execution, rendering it irrelevant for broad external threat defense at the device level.

C. SOAR
SOAR automates incident workflows and orchestrates responses across tools like SIEM or EDR, enhancing efficiency but not providing native detection or protection on endpoints. As a coordination layer, it depends on underlying sensors for data, so it cannot independently add endpoint defense against external threats, potentially leaving OS-diverse devices exposed without integrated detection mechanisms.

Reference:
https://www.comptia.org/certifications/security

Summary
The malware requires an internet connection to activate its conditional triggers, posing a significant risk of data exfiltration or communication with a command-and-control (C2) server if analyzed on a connected network. The most effective and secure method is to use a dedicated, isolated sandbox environment. An online sandbox service is specifically designed for this purpose, providing a safe, instrumented, and disconnected virtual environment where the malware can be detonated and observed without any risk to the organization's production network.

Correct Option

D. Subscribe to an online service to create a sandbox environment.
Commercial online sandboxes (e.g., Any.run, Hybrid Analysis, Cuckoo Sandbox) provide pre-configured, isolated virtual environments that are disconnected from the organization's network.

These services allow the malware to connect to the internet from their own isolated environment, enabling the analyst to observe its full behavior (including C2 communication and polymorphic changes) while containing all malicious activity. This provides deep analysis without any risk of lateral movement or data exfiltration from the corporate network.

Incorrect Options

A. Utilize an RDP session on an unused workstation to evaluate the malware.
This is highly risky. If the "unused workstation" is connected to the corporate network, the malware could still propagate, perform lateral movement, or call home, compromising the entire organization. The RDP session itself could also be a vector for the malware to spread.

B. Disconnect and utilize an existing infected asset off the network.
While disconnecting the network prevents immediate C2 communication, it also prevents the analyst from observing the malware's core conditional triggers that require the internet. This method would yield an incomplete analysis, as the most critical malicious behaviors would not be triggered.

C. Create a virtual host for testing on the security analyst workstation.
This is extremely dangerous. Even with virtualized hosts, there is a risk of VM escape, especially with sophisticated malware. Furthermore, if the host machine is connected to the corporate network for the analyst's daily work, the malware could potentially find a way to bridge to the corporate network, leading to a compromise.

Reference
NIST Special Publication 800-83 (Guide to Malware Incident Prevention and Handling): This guide recommends the use of isolated analysis environments for dynamic malware analysis. It emphasizes that these environments "should be logically or physically separated from production networks" to prevent the malware from spreading or causing damage, which is the core function of a dedicated online sandbox service.

Summary
The scenario specifies that only the firewall data feed has failed, while other intelligence feeds continue to function. This points to a problem specific to the connection or authentication between the enrichment tool and the firewall. A common cause for such a sudden, specific failure in automated system-to-system communication is a change in authentication status. A locked service account would immediately prevent the enrichment tool from authenticating to the firewall's API or logging system to pull data, while leaving other, independently authenticated feeds unaffected.

Correct Option

A. The firewall service account was locked out.
Security tools typically use a dedicated service account with appropriate permissions to automatically pull logs and data from devices like firewalls. If this account becomes locked out due to failed login attempts, password expiration, or an administrative action, the data feed will immediately fail.

This explains the specificity of the failure (only the firewall feed is down) and its sudden nature, as account lockouts can occur without warning. The other intelligence feeds use different connection methods and credentials, so they remain operational.

Incorrect Options

B. The firewall was using a paid feed.
This refers to the firewall receiving threat intelligence, not the analyst's tool receiving data from the firewall. The issue is about exporting the firewall's own log data for enrichment. A subscription lapse on an inbound intelligence feed to the firewall would not affect the outbound flow of its connection logs.

C. The firewall certificate expired.
While a certificate expiration could disrupt a TLS-encrypted connection, it is less likely than an account lockout for a few reasons. Certificates typically have a long validity period and warn before expiring. Also, such an expiration might affect multiple services, not just a single data feed, and would often result in a different error message related to trust or handshake failure.

D. The firewall failed open.
"Fail open" is a network traffic handling state for a firewall. If a firewall fails, it might allow all traffic through instead of blocking it. This is a operational state affecting network traffic, not its ability to generate and export its own log data to a security tool. The firewall can be operational and passing traffic (even incorrectly) while its management plane and logging functions remain active.

Reference
NIST Special Publication 800-53 (Security and Privacy Controls for Information Systems and Organizations): Control IA-5 deals with authenticator management. It highlights the importance of managing service accounts, including password policies and handling lockout conditions, as these are common points of failure for automated system integrations, precisely as described in this scenario.

Summary
A vulnerability scan report is a technical document designed to communicate the specific findings of a security assessment to stakeholders who need to understand and remediate the risks. Its primary purpose is to detail what was found, where it was found, and how severe it is. Therefore, it must include a list of the systems affected by each vulnerability and a standardized metric that quantifies the severity of the finding to enable prioritization.

Correct Options

D. Affected hosts
This is a fundamental component of any vulnerability scan report. It provides the essential context of where the vulnerability is located. Without a list of specific IP addresses, hostnames, or asset tags, remediation teams cannot locate and fix the vulnerable systems. It answers the critical question: "Which servers, workstations, or devices are impacted?"

E. Risk score
A risk score, typically derived from the Common Vulnerability Scoring System (CVSS), provides a standardized, quantitative measure of a vulnerability's severity. This allows security teams and management to prioritize remediation efforts effectively, focusing on the most critical issues first (e.g., Critical and High severity vulnerabilities) to reduce risk most efficiently.

Incorrect Options

A. Lessons learned
This is an element of a post-incident report or a lessons-learned meeting following a security incident. It is a retrospective analysis of what went wrong in the response process and is not part of the standard output of a routine vulnerability scan.

B. Service-level agreement
A Service-Level Agreement (SLA) is a contractual document that defines the expected level of service between a provider and a customer. It is not a component of a technical findings report like a vulnerability scan report.

C. Playbook
A playbook is a predefined set of procedures for responding to a specific type of security incident or alert. It is an operational document used by the SOC for response, not a finding included in a vulnerability assessment report.

F. Education plan
An education or training plan is a strategic document for improving security awareness among staff. While vulnerability scan results might inform the topics of a training plan, the plan itself is not included within the scan report.

Reference
NIST Special Publication 800-40 (Guide to Enterprise Patch Management Technologies): While focused on patching, this guide emphasizes the importance of vulnerability assessment reports that include details on "the specific machines affected" (affected hosts) and "the severity of the vulnerabilities" (risk score) to enable effective and prioritized remediation.

Summary
In a legal context involving evidence preservation, the paramount concern is ensuring the data's integrity and proving it has not been altered from the moment it was collected. This is achieved through a forensic process that creates a verifiable, bit-for-bit copy of the original media. Generating a cryptographic hash of the original drive and the copy provides a mathematical seal that can be used in court to prove the evidence is authentic and unmodified.

Correct Option

A. Generate a hash value and make a backup image.
This is the standard forensic procedure for evidence preservation. A forensic image is a sector-by-sector copy of the entire hard drive, capturing all data, including deleted files and slack space.

Generating a cryptographic hash (like SHA-256) of the original drive before imaging and then of the resulting image file provides a unique digital fingerprint. If the hashes match, it proves in a court of law that the image is an exact, unaltered replica of the original evidence, preserving the chain of custody and data integrity.

Incorrect Options

B. Encrypt the device to ensure confidentiality of the data.
Encryption protects confidentiality but does nothing to prove the data hasn't been modified. In fact, if the original evidence is encrypted after seizure, it could raise questions about its authenticity and make the forensic imaging process more complex.

C. Protect the device with a complex password.
A password only restricts access; it does not prevent the data on the drive from being altered. Furthermore, a forensic image is needed to access the data without potentially altering metadata (like last accessed timestamps) on the original drive.

D. Perform a memory scan dump to collect residual data.
A memory dump captures the contents of RAM, which is volatile memory. This is a separate procedure used to collect evidence of running processes and is irrelevant to the task of preserving the long-term data stored on a non-volatile hard drive for litigation.

Reference
NIST Special Publication 800-86 (Guide to Integrating Forensic Techniques into Incident Response): This guide outlines the fundamental principles of forensic evidence collection. It prescribes creating a forensic copy (image) of the original media and using cryptographic hash algorithms to verify the integrity of the evidence throughout its lifecycle, ensuring it is admissible in legal proceedings.

Summary
Layer 4 DDoS attacks, such as SYN floods or UDP reflection attacks, target the transport layer by exhausting server resources like connection tables. A Content Delivery Network (CDN) is specifically designed to absorb these types of high-volume, network-level attacks. It acts as a distributed proxy, scrubbing malicious traffic across its global network of servers before allowing only clean traffic to reach the origin infrastructure, thus preventing resource exhaustion at the target.

Correct Option

C. Roll out a CDN.
A CDN operates as a large, distributed buffer between the internet and your origin server. It has the massive bandwidth and specialized DDoS mitigation capacity to absorb and filter out Layer 4 flood traffic.

By serving as the public-facing endpoint, the CDN ensures that only legitimate, scrubbed user requests are passed through to the origin web server. This effectively mitigates the attack by preventing the flood of packets from ever reaching the company's network perimeter and consuming server resources.

Incorrect Options

A. Block the attacks using firewall rules.
While firewalls can block traffic by IP or port, they lack the sophistication and scale to handle a large-scale DDoS flood. A firewall running on limited hardware can itself be overwhelmed by the sheer volume of packets, becoming a bottleneck and failing. It is not designed for volumetric attack mitigation.

B. Deploy an IPS in the perimeter network.
An Intrusion Prevention System (IPS) is designed to detect and block malicious content and exploits within traffic streams (Layer 7). It is ineffective against the raw packet flood of a Layer 4 DDoS attack, which does not rely on malicious payloads but on volume. The IPS would also be overwhelmed by the high packet rate.

D. Implement a load balancer.
A load balancer distributes traffic across multiple servers to handle high legitimate load. However, it cannot distinguish between legitimate and malicious traffic in a DDoS flood. It will simply distribute the attack traffic, causing all backend servers to become overwhelmed and fail. It does not "scrub" or filter malicious traffic.

Reference
CISA (Cybersecurity and Infrastructure Security Agency) - Understanding and Responding to Distributed Denial-of-Service Attacks: CISA guidance recommends using "content distribution networks (CDNs)" and DDoS mitigation services as a primary defense against volumetric attacks. These services are designed to handle the massive scale of traffic that characterizes Layer 3/4 DDoS attacks, which on-premise devices like firewalls and IPS cannot withstand.