CompTIA CAS-005 - CompTIA SecurityX Certification Exam

The malware uses TCP 4444 to move laterally between systems. A host-based firewall can block unauthorized communication ports (like TCP 4444) on each workstation, preventing malware from establishing connections and spreading. Configuring the CPU's NX bit and enabling ASLR primarily help in mitigating memory-based exploits, not in stopping lateral movement. Enabling UEFI ensures boot integrity but does not mitigate active lateral communication. An edge firewall would protect the network perimeter, not internal workstation-to-workstation communication.

Step by Step Explanation:

Understanding the Scenario: The question focuses on the historical design assumptions behind older operational technology (OT)systems, particularly in the context of command, control, and telemetry.

Analyzing the Answer Choices:

A. operating in an isolated/disconnected system: This is the most accurate assumption for many legacy OT systems. Historically, these systems weredesigned to operate in air-gapped environments, completely isolated from external networks (including the internet).

The logs show that the user connected fromToronto (104.18.16.29)andLos Angeles (95.67.137.12)within minutes. The sudden location change is a typical trigger forgeoblocking in a Next-Generation Firewall (NGFW), leading to theHR System being denied.

A compromised account (B)would show failed login attempts or unusual activities, but all other access attempts were allowed.

Business hours restriction (C)is unlikely since the user was granted access earlier.

Approved subnet issues (D)would affect all applications, not just HR System access.

The issue is tracing the original source of requests in a tiered architecture with a load balancer. The web server logs show internal IPs (192.168.1.10), not the external client IPs, because the load balancer forwards requests without preserving the source. Enabling theX-Forwarded-Forheader on the load balancer adds the client’s original IP to the HTTP request headers, allowing downstream servers to log it. This ensures traceability without altering the architecture significantly.

Option A:Correct—X-Forwarded-For is the standard solution for preserving client IPs through load balancers.

Option B:A Host-based Intrusion Detection System (HIDS) detects anomalies but doesn’t address IP traceability.

Option C:A trusted CA certificate fixes the self-signed warning but is unrelated to source tracking.

Option D:Stored procedures improve database security but don’t help with IP logging.

Option E:Storing $_SERVER['REMOTE_ADDR'] captures the loadbalancer’s IP, not the client’s, unless X-Forwarded-For is enabled.

The log-in activity indicates a security threat, particularly involving the ADMIN account with a high-risk failure status. This suggests that the account may be targeted by malicious activities such as credential stuffing or brute force attacks.

Updating log configuration settings (A) may help in better logging future activities but does not address the immediate threat.

Changing the admin account password (B) is a good practice but may not fully mitigate the ongoing threat if the account has already been compromised.

Blocking employees (C) from logging into non-business applications might help in reducing attack surfaces but doesn't directly address the compromised account issue.

Implementing automation to disable accounts associated with high-risk activities ensures an immediate response to the detected threat, preventing further unauthorized access and allowing time for thorough investigation and remediation.

Step-by-Step Explanation:

Runtime Application Self-Protection (RASP) (A)monitors and protects applications in real time by detecting and blocking attacks as they occur. Unlike traditional security solutions, RASP is integrated into the application itself, meaning it works regardless of the programming language used. It effectively mitigates common vulnerabilities such as SQL injection, XSS, and buffer overflows.

Dynamic Application Security Testing (DAST) (C) is a passive scanning approach that may not prevent attacks in real-time, while Network Intrusion PreventionSystems (NIPS) (D) focuses on network traffic, not application-layer security.

RACI matrix(Responsible, Accountable, Consulted, Informed) is used for role mapping across the project lifecycle.

CMDB is a configuration inventory; ITIL is a framework. Recall trees are for disaster recovery/business continuity.

FromCAS-005, Domain 1: Security Governance and Compliance:

“The RACI matrix is essential in role assignment and accountability for software development and operational processes.”

Static Application Security Testing (SAST) involves analyzing source code or compiled code for security vulnerabilities without executing the program. This method is well-suited for identifying syntax errors, coding standards violations, and potential security issues early in the development lifecycle.

A. Static application security testing (SAST): SAST tools analyze the source code to detect syntax errors, vulnerabilities, and other issues before the code is run. This is the most relevant task for the DevSecOps team to identify syntax errors and improve code quality.

B. Software composition analysis: This focuses on identifying vulnerabilities in open-source components and libraries used in the application but does not address syntax errors directly.

C. Runtime application self-protection (RASP): RASP involves monitoring and protecting applications during runtime, which does not help in identifying syntax errors during the development phase.

D. Web application vulnerability scanning: This involves scanning the running application for vulnerabilities but does not address syntax errors in the code.

Step by Step Explanation:

Understanding the Scenario: The question describes a proactive security measure where an organization maintains a registry of software dependencies and their corresponding hashes. This registry is used to verify the integrity of software packages.

Analyzing the Answer Choices:

A. Supply chain attack: This type of attack involves compromising the software supply chain by injecting malicious code into legitimate software packages.

Unauthorized code changesand lack ofindependent verificationare directly mitigated bycode signing, which ensures that code is from a trusted source and has not been altered.

While digital signatures are part of code signing, the broader practice of code signing encompasses signature management, version integrity, and trusted sources.

Lightweight cryptography is irrelevant in this context; it's more about efficiency in constrained devices.

Non-repudiation is a benefit of digital signatures but doesn't directly solve the verification/integrity concerns alone.

FromCAS-005 Guide, Domain 4: Security Architecture, Tools, and Technologies:

“Code signing ensures that the code has not been tampered with and originates from a trusted developer.”