CAS-005 Exam Dumps - CompTIA SecurityX Certification Exam

The sshd_config file is the main configuration file for the OpenSSH server. To disable weak CBC (Cipher Block Chaining) ciphers for SSH connections, the security engineer should modify the sshd_config file to update the list of allowed ciphers. This file typically contains settings for the SSH daemon, including which encryption algorithms are allowed.

By editing the /etc/ssh/sshd_config file and updating the Ciphers directive, weak ciphers can be removed, and only strong ciphers can be allowed. This change ensures that the SSH server does not use insecure encryption methods.

In the context of improving incident response and reducing dwell time, the security analyst needs to focus on proactive measures that can quickly detect and alert on potential security breaches. Here’s a detailed analysis of the options provided:

A. Adjusting the SIEM to alert on attempts to visit phishing sites: While this is a useful measure to prevent phishing attacks, it primarily addresses external threats and doesn’t directly impact dwell time reduction, which focuses on the time a threat remains undetected within a network.

B. Allowing TRACE method traffic to enable better log correlation: The TRACE method in HTTP is used for debugging purposes, but enabling it can introduce security vulnerabilities. It’s not typically recommended for enhancing security monitoring or incident response.

C. Enabling alerting on all suspicious administrator behavior: This option directly targets the potential misuse of administrator accounts, which are often high-value targets for attackers. By monitoring and alerting on suspicious activities from admin accounts, the organization can quickly identify and respond to potential breaches, thereby reducing dwell time significantly. Suspicious behavior could include unusual login times, access to sensitive data not usually accessed by the admin, or any deviation from normal behavior patterns. This proactive monitoring is crucial for quick detection and response, aligning well with best practices in incident response.

D. Utilizing allow lists on the WAF for all users using GET methods: This measure is aimed at restricting access based on allowed lists, which can be effective in preventing unauthorized access but doesn’t specifically address the need for quick detection and response to internal threats.

The key requirement is toinstantly eliminate data losson a lost device.

Cryptographic erasureworks by deleting encryption keys used for FDE (full disk encryption), rendering all data unrecoverable within seconds — satisfying the "mitigate within seconds" requirement.

Revoking certificates won’t wipe the data from a lost tablet.

Changing MFA credentials won’t help unless the device is secured, and app allow lists don’t apply post-loss.

FromCAS-005, Domain 3: Secure Systems Design and Deployment:

“Cryptographic erase (CE) renders data irrecoverable by deleting encryption keys used to protect data on the device.”

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.”

Comprehensive and Detailed 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).

Based on the provided authentication logs, we observe that User1's accountexperienced multiple failed login attempts within a very short time span (at 8:01:23 AM on 12/15). This pattern indicates a potential brute-force attack or an attempt to gain unauthorized access. Here’s a breakdown of why disabling User1's account is the appropriate first step:

Failed Login Attempts: The logs show that User1 had four consecutive failed login attempts:

VM01 at 8:01:23 AM

VM08 at 8:01:23 AM

VM01 at 8:01:23 AM

VM08 at 8:01:23 AM

Security Protocols and Best Practices: According to CompTIA Security+ guidelines, multiple failed login attempts within a short timeframe should trigger an immediate response to prevent further potential unauthorized access attempts. This typically involves temporarily disabling the account to stop ongoing brute-force attacks.

Account Lockout Policy: Implementing an account lockout policy is a standard practice to thwart brute-force attacks. Disabling User1's account will align with these best practices and prevent further failed attempts, which might lead to successful unauthorized access if not addressed.

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 question states that security scanning and quality assurance (QA) in the CI/CD pipeline have been completed with no issues, indicating that the code in the test branch is ready for production. According to the CompTIA SecurityX CAS-005 study guide (Domain 2: Security Operations, 2.3), in a secure CI/CD pipeline, once code passes automated security scans, QA, and other checks (e.g., unit testing, peer reviews), the next step is to merge the tested branch into the main branch for deployment to production.

Option B:Threat modeling is typically performed earlier, during design or development, not after passing CI/CD checks.

Option C:Unit testing is part of the CI/CD pipeline and should already be completed.

Option D:Peer reviews are conducted before or during the test phase, not after QAand security scans are clear.

Option A:Merging the test branch to the main branch is the logical next step to prepare for production deployment.