CompTIA CompTIA Certifications CS0-003 Questions & Answers

• Question 111:

  A security analyst reviews the following results of a Nikto scan:

  

  Which of the following should the security administrator investigate next?

  A. tiki

  B. phpList

  C. shtml.exe

  D. sshome

  Correct Answer: C

  The security administrator should investigate shtml.exe next, as it is a potential vulnerability that allows remote code execution on the web server. Nikto scan results indicate that the web server is running Apache on Windows, and that the shtml.exe file is accessible in the /scripts/ directory. This file is part of the Server Side Includes (SSI) feature, which allows dynamic content generation on web pages. However, if the SSI feature is not configured properly, it can allow attackers to execute arbitrary commands on the web server by injecting malicious code into the URL or the web page12. Therefore, the security administrator should check the SSI configuration and permissions, and remove or disable the shtml.exe file if it is not needed. References: Nikto-Penetration testing. Introduction, Web application scanning with Nikto

• Question 112:

  Which of the following is a nation-state actor least likely to be concerned with?

  A. Detection by MITRE ATTandCK framework.

  B. Detection or prevention of reconnaissance activities.

  C. Examination of its actions and objectives.

  D. Forensic analysis for legal action of the actions taken

  Correct Answer: D

  A nation-state actor is a group or individual that conducts cyberattacks on behalf of a government or a political entity. They are usually motivated by national interests, such as espionage, sabotage, or influence operations. They are often highly skilled, resourced, and persistent, and they operate with the protection or support of their state sponsors. Therefore, they are less likely to be concerned with the forensic analysis for legal action of their actions, as they are unlikely to face prosecution or extradition in their own country or by international law. They are more likely to be concerned with the detection by the MITRE ATTandCK framework, which is a knowledge base of adversary tactics and techniques based on real-world observations. The MITRE ATTandCK framework can help defenders identify, prevent, and respond to cyberattacks by nation-state actors. They are also likely to be concerned with the detection or prevention of reconnaissance activities, which are the preliminary steps of cyberattacks that involve gathering information about the target, such as vulnerabilities, network topology, or user credentials. Reconnaissance activities can expose the presence, intent, and capabilities of the attackers, and allow defenders to take countermeasures. Finally, they are likely to be concerned with the examination of their actions and objectives, which can reveal their motives, strategies, and goals, and help defenders understand their threat profile and attribution. References:

  1: MITRE ATTandCK?

  2: What is the MITRE ATTandCK Framework? | IBM

  3: MITRE ATTandCK | MITRE

  4: Cyber Forensics Explained: Reasons, Phases and Challenges of Cyber Forensics | Splunk

  5: Digital Forensics: How to Identify the Cause of a Cyber Attack - G2

• Question 113:

  A vulnerability management team found four major vulnerabilities during an assessment and needs to provide a report for the proper prioritization for further mitigation. Which of the following vulnerabilities should have the highest priority for the mitigation process?

  A. A vulnerability that has related threats and loCs, targeting a different industry

  B. A vulnerability that is related to a specific adversary campaign, with loCs found in the SIEM

  C. A vulnerability that has no adversaries using it or associated loCs

  D. A vulnerability that is related to an isolated system, with no loCs

  Correct Answer: B

  A vulnerability that is related to a specific adversary campaign, with IoCs found in the SIEM, should have the highest priority for the mitigation process. This is because it indicates that the vulnerability is actively being exploited by a known

  threat actor, and that the organization's security monitoring system has detected signs of compromise. This poses a high risk of data breach, service disruption, or other adverse impacts. References:

  How to Prioritize Vulnerabilities Effectively: Vulnerability Prioritization Explained, Section:

  How to prioritize vulnerabilities step by step to avoid drowning in sea of problems; CompTIA CySA+ Study Guide: S0-003, 3rd Edition, Chapter 4: Security Operations and Monitoring, page 156.

• Question 114:

  Which of the following techniques would be best to provide the necessary assurance for embedded software that drives centrifugal pumps at a power Plant?

  A. Containerization

  B. Manual code reviews

  C. Static and dynamic analysis

  D. Formal methods

  Correct Answer: D

  According to the CompTIA CySA+ Study Guide: S0-003, 3rd Edition1, the best technique to provide the necessary assurance for embedded software that drives centrifugal pumps at a power plant is formal methods. Formal methods are a rigorous and mathematical approach to software development and verification, which can ensure the correctness and reliability of critical software systems. Formal methods can be used to specify, design, implement, and verify embedded software using formal languages, logics, and tools1. Containerization, manual code reviews, and static and dynamic analysis are also useful techniques for software assurance, but they are not as rigorous or comprehensive as formal methods. Containerization is a method of isolating and packaging software applications with their dependencies, which can improve security, portability, and scalability. Manual code reviews are a process of examining the source code of a software program by human reviewers, which can help identify errors, vulnerabilities, and compliance issues. Static and dynamic analysis are techniques of testing and evaluating software without executing it (static) or while executing it (dynamic), which can help detect bugs, defects, and performance issues1.

• Question 115:

  An analyst is evaluating a vulnerability management dashboard. The analyst sees that a previously remediated vulnerability has reappeared on a database server. Which of the following is the most likely cause?

  A. The finding is a false positive and should be ignored.

  B. A rollback had been executed on the instance.

  C. The vulnerability scanner was configured without credentials.

  D. The vulnerability management software needs to be updated.

  Correct Answer: B

  A rollback had been executed on the instance. If a database server is restored to a previous state, it may reintroduce a vulnerability that was previously fixed. This can happen due to backup and recovery operations, configuration changes, or software updates. A rollback can undo the patching or mitigation actions that were applied to remediate the vulnerability. References: Vulnerability Remediation: It's Not Just Patching, Section: The Remediation Process; Vulnerability assessment for SQL Server, Section: Remediation

• Question 116:

  A cybersecurity analyst is doing triage in a SIEM and notices that the time stamps between the firewall and the host under investigation are off by 43 minutes. Which of the following is the most likely scenario occurring with the time stamps?

  A. The NTP server is not configured on the host.

  B. The cybersecurity analyst is looking at the wrong information.

  C. The firewall is using UTC time.

  D. The host with the logs is offline.

  Correct Answer: A

  The most likely scenario occurring with the time stamps is that the NTP server is not configured on the host. NTP is the Network Time Protocol, which is used to synchronize the clocks of computers over a network. NTP uses a hierarchical system of time sources, where each level is assigned a stratum number. The most accurate time sources, such as atomic clocks or GPS receivers, are at stratum 0, and the devices that synchronize with them are at stratum 1, and so on. NTP clients can query multiple NTP servers and use algorithms to select the best time source and adjust their clocks accordingly1. If the NTP server is not configured on the host, the host will rely on its own hardware clock, which may drift over time and become inaccurate. This can cause discrepancies in the time stamps between the host and other devices on the network, such as the firewall, which may be synchronized with a different NTP server or use a different time zone. This can affect the security analysis and correlation of events, as well as the compliance and auditing of the network.

• Question 117:

  Which of the following threat-modeling procedures is in the OWASP Web Security Testing Guide?

  A. Review Of security requirements

  B. Compliance checks

  C. Decomposing the application

  D. Security by design

  Correct Answer: C

  The OWASP Web Security Testing Guide (WSTG) includes a section on threat modeling, which is a structured approach to identify, quantify, and address the security risks associated with an application. The first step in the threat modeling process is decomposing the application, which involves creating use cases, identifying entry points, assets, trust levels, and data flow diagrams for the application. This helps to understand the application and how it interacts with external entities, as well as to identify potential threats and vulnerabilities1. The other options are not part of the OWASP WSTG threat modeling process.

• Question 118:

  A security analyst detects an email server that had been compromised in the internal network. Users have been reporting strange messages in their email inboxes and unusual network traffic. Which of the following incident response steps should be performed next?

  A. Preparation

  B. Validation

  C. Containment

  D. Eradication

  Correct Answer: C

  After detecting a compromised email server and unusual network traffic, the next step in incident response is containment, to prevent further damage or spread of the compromise. References: CompTIA CySA+ Study Guide: S0-003, 3rd Edition, Chapter 5: Incident Response, page 197.

• Question 119:

  A security analyst has found the following suspicious DNS traffic while analyzing a packet capture:

  1.

  DNS traffic while a tunneling session is active.

  2.

  The mean time between queries is less than one second.

  3.

  The average query length exceeds 100 characters.

  Which of the following attacks most likely occurred?

  A. DNS exfiltration

  B. DNS spoofing

  C. DNS zone transfer

  D. DNS poisoning

  Correct Answer: A

  DNS exfiltration is a technique that uses the DNS protocol to transfer data from a compromised network or device to an attacker-controlled server. DNS exfiltration can bypass firewall rules and security products that do not inspect DNS traffic.

  The characteristics of the suspicious DNS traffic in the question match the indicators of DNS exfiltration, such as:

  DNS traffic while a tunneling session is active: This implies that the DNS protocol is being used to create a covert channel for data transfer. The mean time between queries is less than one second: This implies that the DNS queries are being

  sent at a high frequency to maximize the amount of data transferred.

  The average query length exceeds 100 characters: This implies that the DNS queries are encoding large amounts of data in the subdomains or other fields of the DNS packets.

  Official References:

  https://partners.comptia.org/docs/default-source/resources/comptia-cysa-cs0-002- exam-objectives

  https://resources.infosecinstitute.com/topic/bypassing-security-products-via-dns- data-exfiltration/ https://www.reddit.com/r/CompTIA/comments/nvjuzt/dns_exfiltration_explanation/

• Question 120:

  An analyst is evaluating the following vulnerability report:

  

  Which of the following vulnerability report sections provides information about the level of impact on data confidentiality if a successful exploitation occurs?

  A. Payloads

  B. Metrics

  C. Vulnerability

  D. Profile

  Correct Answer: B

  The Metrics section of the vulnerability report provides information about the level of impact on data confidentiality if a successful exploitation occurs. The Metrics section contains the CVE dictionary entry and the CVSS base score of the vulnerability. CVE stands for Common Vulnerabilities and Exposures and it is a standardized system for identifying and naming vulnerabilities. CVSS stands for Common Vulnerability Scoring System and it is a standardized system for measuring and rating the severity of vulnerabilities. The CVSS base score is a numerical value between 0 and 10 that reflects the intrinsic characteristics of a vulnerability, such as its exploitability, impact, and scope. The CVSS base score is composed of three metric groups: Base, Temporal, and Environmental. The Base metric group captures the characteristics of a vulnerability that are constant over time and across user environments. The Base metric group consists of six metrics: Attack Vector, Attack Complexity, Privileges Required, User Interaction, Scope, and Impact. The Impact metric measures the effect of a vulnerability on the confidentiality, integrity, and availability of the affected resources. In this case, the CVSS base score of the vulnerability is 9.8, which indicates a critical severity level. The Impact metric of the CVSS base score is 6.0, which indicates a high impact on confidentiality, integrity, and availability. Therefore, the Metrics section provides information about the level of impact on data confidentiality if a successful exploitation occurs. The other sections of the vulnerability report do not provide information about the level of impact on data confidentiality if a successful exploitation occurs. The Payloads section contains links to request and response payloads that demonstrate how the vulnerability can be exploited. The Payloads section can help an analyst to understand how the attack works, but it does not provide a quantitative measure of the impact. The Vulnerability section contains information about the type, group, and description of the vulnerability. The Vulnerability section can help an analyst to identify and classify the vulnerability, but it does not provide a numerical value of the impact. The Profile section contains information about the authentication, times viewed, and aggressiveness of the vulnerability. The Profile section can help an analyst to assess the risk and priority of the vulnerability, but it does not provide a specific measure of the impact on data confidentiality. References:

  [1] CVE - Common Vulnerabilities and Exposures (CVE) [2] Common Vulnerability Scoring System SIG

  [3] CVSS v3.1 Specification Document

  [4] CVSS v3.1 User Guide

  [5] How to Read a Vulnerability Report - Security Boulevard