CompTIA CS0-003 Online Practice Questions and Exam Preparation

CompTIA CS0-003 Online Questions & Answers

• Question 591:

  Which of the following is the best reason to implement an MOU?

  A. To create a business process for configuration management
  B. To allow internal departments to understand security responsibilities
  C. To allow an expectation process to be defined for legacy systems
  D. To ensure that all metrics on service levels are properly reported
  B. To allow internal departments to understand security responsibilities

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  Explanation

  A Memorandum of Understanding (MOU) is a formal agreement that outlines the roles and responsibilities of each party involved in a particular process or project, especially within security frameworks. In the context of cybersecurity, an MOU is commonly used to clarify and document the security responsibilities of different departments or entities involved. It helps ensure everyone understands their specific duties and contributions to security, which is crucial for coordination and risk management. According to CompTIA Security+ guidelines, while options A, C, and D describe other forms of agreements, they do not capture the essential purpose of an MOU as accurately as option B does.

• Question 592:

  A security analyst is performing a malware analysis on a device and receives the following instructions:

  1. Reduce the blast radius of the potential threat.

  2. Preserve forensic data for post-incident analysis.

  3. If securely possible, preserve connectivity for live analysis.

  Which of the following will best help the analyst during the investigation?

  A. Configure an EDR agent to isolate the network with authorized exceptions to the NOC VLAN.
  B. Execute a SOAR playbook to trigger a malware scan on the company's assets.
  C. Use file integrity monitoring to determine if the suspicious file was modified.
  D. Collect the suspicious file using SFTP and reimage the device.
  A. Configure an EDR agent to isolate the network with authorized exceptions to the NOC VLAN.

• Question 593:

  A recent audit of the vulnerability management program outlined the finding for increased awareness of secure coding practices.

  Which of the following would be best to address the finding?

  A. Establish quarterly SDLC training on the top vulnerabilities for developers
  B. Conduct a yearly inspection of the code repositories and provide the report to management.
  C. Hire an external penetration test of the network
  D. Deploy more vulnerability scanners for increased coverage
  A. Establish quarterly SDLC training on the top vulnerabilities for developers

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  Explanation

  The finding in the audit suggests a need to improve awareness of secure coding practices. The most appropriate action to address this finding is to provide training to the development team on secure coding practices.

• Question 594:

  A security analyst observes a daily traffic spike from the same subnet with a history of DDoS and reconnaissance flags.

  What should the analyst do first?

  A. Recommend denying all traffic from the subnet via firewall
  B. Continue monitoring as no security concerns were triggered
  C. Review network logs to identify traffic context and actions taken
  D. Check resource consumption for device performance issues
  C. Review network logs to identify traffic context and actions taken

• Question 595:

  A security team identified several rogue Wi-Fi access points during the most recent network scan. The network scans occur once per quarter.

  Which of the following controls would best all ow the organization to identity rogue devices more quickly?

  A. Implement a continuous monitoring policy.
  B. Implement a BYOD policy.
  C. Implement a portable wireless scanning policy.
  D. Change the frequency of network scans to once per month.
  A. Implement a continuous monitoring policy.

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  Explanation

  The best control to allow the organization to identify rogue devices more quickly is A. Implement a continuous monitoring policy. A continuous monitoring policy is a set of procedures and tools that enable an organization to detect and respond to unauthorized or anomalous activities on its network in real time or near real time. A continuous monitoring policy can help identify rogue access points as soon as they appear on the network, rather than waiting for quarterly or monthly scans. A continuous monitoring policy can also help improve the overall security posture and compliance of the organization by providing timely and accurate information about its network assets, vulnerabilities, threats, and incidents 1.

• Question 596:

  An incident response team is assessing ransomware attack vectors with no indication of network-based intrusion.

  What is the most likely root cause?

  A. USB drop
  B. LFI
  C. Cross-site forgery
  D. SQL injection
  A. USB drop

• Question 597:

  While a security analyst for an organization was reviewing logs from web servers. the analyst found several successful attempts to downgrade HTTPS sessions to use cipher modes of operation susceptible to padding oracle attacks.

  Which of the following combinations of configuration changes should the organization make to remediate this issue?

  (Select two).

  A. Configure the server to prefer TLS 1.3.
  B. Remove cipher suites that use CBC.
  C. Configure the server to prefer ephemeral modes for key exchange.
  D. Require client browsers to present a user certificate for mutual authentication.
  E. Configure the server to require HSTS.
  F. Remove cipher suites that use GCM.
  A. Configure the server to prefer TLS 1.3.
  B. Remove cipher suites that use CBC.

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  Explanation

  A padding oracle attack is a type of attack that exploits the padding validation of a cryptographic message to decrypt the ciphertext without knowing the key. A padding oracle is a system that responds to queries about whether a message has a valid padding or not, such as a web server that returns different error messages for invalid padding or invalid MAC. A padding oracle attack can be applied to the CBC mode of operation, where the attacker can manipulate the ciphertext blocks and use the oracle's responses to recover the plaintext 12.

  To remediate this issue, the organization should make the following configuration changes: Configure the server to prefer TLS 1.3. TLS 1.3 is the latest version of the Transport Layer Security protocol, which provides secure communication between clients and servers. TLS 1.3 has several security improvements over previous versions, such as: Remove cipher suites that use CBC. Cipher suites are combinations of cryptographic algorithms that specify how TLS connections are secured. Cipher suites that use CBC mode are vulnerable to padding oracle attacks, as well as other attacks such as BEAST and Lucky 13. Therefore, they should be removed from the server's configuration and replaced with cipher suites that use more secure modes of operation, such as GCM or CCM78. The other options are not effective or necessary to remediate this issue.

  Option C is not effective because configuring the server to prefer ephemeral modes for key exchange does not prevent padding oracle attacks. Ephemeral modes for key exchange are methods that generate temporary and random keys for each session, such as Diffie-Hellman or Elliptic Curve Diffie-Hellman. Ephemeral modes provide forward secrecy, which means that compromising the long-term keys does not affect the security of past sessions. However, ephemeral modes do not protect against padding oracle attacks, which exploit the padding validation of the ciphertext rather than the key exchange 9.

  Option D is not necessary because requiring client browsers to present a user certificate for mutual authentication does not prevent padding oracle attacks. Mutual authentication is a process that verifies the identity of both parties in a communication, such as using certificates or passwords. Mutual authentication enhances security by preventing impersonation or spoofing attacks. However, mutual authentication does not protect against padding oracle attacks, which exploit the padding validation of the ciphertext rather than the authentication.

  Option E is not necessary because configuring the server to require HSTS does not prevent padding oracle attacks. HSTS stands for HTTP Strict Transport Security and it is a mechanism that forces browsers to use HTTPS connections instead of HTTP connections when communicating with a web server. HSTS enhances security by preventing downgrade or man-in-the-middle attacks that try to intercept or modify HTTP traffic. However, HSTS does not protect against padding oracle attacks, which exploit the padding validation of HTTPS traffic rather than the protocol.

  Option F is not effective because removing cipher suites that use GCM does not prevent padding oracle attacks. GCM stands for Galois/ Counter Mode and it is a mode of operation that provides both encryption and authentication for block ciphers, such as AES. GCM is more secure and efficient than CBC mode, as it prevents various types of attacks, such as padding oracle, BEAST, Lucky 13, and IV reuse attacks. Therefore, removing cipher suites that use GCM would reduce security rather than enhance it .

  References:

  1 Padding oracle attack - Wikipedia

  2 flast101/padding-oracle-attack-explained - GitHub 3 A Cryptographic Analysis of the TLS 1.3 Handshake Protocol | Journal of Cryptology 4 Which block cipher mode of operation does TLS 1.3 use? - Cryptography Stack Exchange 5 The Essentials of Using an Ephemeral Key Under TLS 1.3 6 Guidelines for the Selection, Configuration, and Use of ... - NIST 7 CBC decryption vulnerability - .NET | Microsoft Learn 8 The Padding Oracle Attack | Robert Heaton 9 What is Ephemeral Diffie-Hellman? | Cloudflare [10] What is Mutual TLS? How mTLS Authentication Works | Cloudflare [11] What is HSTS? HTTP Strict Transport Security Explained | Cloudflare [12] Galois/Counter Mode - Wikipedia [13] AES-GCM and its IV/nonce value - Cryptography

  Stack Exchange

• Question 598:

  A company runs a website that allows public posts. Recently, some users report that when visiting the website, pop-ups appear asking the users for their credentials.

  Which of the following is the most likely cause of this issue?

  A. Rootkit
  B. SQL injection
  C. CSRF
  D. XSS
  D. XSS

• Question 599:

  An organization implemented an extensive firewall access-control blocklist to prevent internal network ranges from communicating with a list of IP addresses of known command-and-control domains A security analyst wants to reduce the load on the firewall.

  Which of the following can the analyst implement to achieve similar protection and reduce the load on the firewall?

  A. A DLP system
  B. DNS sinkholing
  C. IP address allow list
  D. An inline IDS
  B. DNS sinkholing

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  Explanation

  DNS sinkholing is a mechanism that can prevent internal network ranges from communicating with a list of IP addresses of known command-and-control domains by returning a false or controlled IP address for those domains. This can reduce the load on the firewall by intercepting the DNS requests before they reach the firewall and diverting them to a sinkhole server. The other options are not relevant or effective for this purpose. CompTIA Cybersecurity Analyst (CySA+)

  Certification Exam Objectives (CS0-002), page 9;

  https://www.enisa.europa.eu/topics/incidentresponse/glossary/dns-sinkhole

• Question 600:

  During an audit, several customer order forms were found to contain inconsistencies between the actual price of an item and the amount charged to the customer. Further investigation narrowed the cause of the issue to manipulation of the public-facing web form used by customers to order products.

  Which of the following would be the best way to locate this issue?

  A. Reduce the session timeout threshold
  B. Deploy MFA for access to the web server.
  C. Implement input validation.
  D. Run a dynamic code analysis.
  C. Implement input validation.

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  Explanation

  During an audit, it was discovered that several customer order forms had inconsistencies between the actual price and the amount charged. Further investigation revealed that the root cause was manipulation of the public-facing web form.

  1. Reducing the session timeout threshold (A) would limit session duration but not address the form manipulation issue.

  2. Deploying MFA (B) enhances authentication security but does not prevent or detect form data manipulation.

  3. Implementing input validation (C) directly prevents malicious or incorrect data from being submitted through the web form by ensuring all inputs meet expected formats and criteria.

  4. Running dynamic code analysis (D) can identify vulnerabilities during runtime but is more complex and less immediate than input validation.

  Therefore, the most effective and immediate step to prevent and locate this issue is to implement input validation, ensuring data integrity and preventing manipulation at the source.