CompTIA Updated CAS-005 Exam Questions and Answers by avneet

To secure the Operational Technology (OT) environment based on the given requirements, the best approach is to implement a bastion host in the OT network. The bastion host serves as a secure entry point for remote access, allowing third-party vendors to connect while being monitored by security tools. Using a dedicated update server for workstations ensures that security updates are applied in a controlled manner without direct internet access.

References:

CompTIA SecurityX Study Guide: Recommends the use of bastion hosts and dedicated update servers for securing OT environments.

NIST Special Publication 800-82, "Guide to Industrial Control Systems (ICS) Security": Advises on isolating OT networks and using secure remote access methods.

"Industrial Network Security" by Eric D. Knapp and Joel Thomas Langill: Discusses strategies for securing OT networks, including the use of bastion hosts and update servers.

To prevent emails from being marked as spam, several DNS records related to email authentication need to be properly configured and updated when there are changes to the email server's certificates:

A. DMARC (Domain-based Message Authentication, Reporting & Conformance): DMARC records help email servers determine how to handle messages that fail SPF or DKIM checks, improving email deliverability and reducing the likelihood of emails being marked as spam.

B. SPF (Sender Policy Framework): SPF records specify which mail servers are authorized to send email on behalf of your domain. Updating the SPF record ensures that the new email server is recognized as an authorized sender.

C. DKIM (DomainKeys Identified Mail): DKIM adds a digital signature to email headers, allowing the receiving server to verify that the email has not been tampered with and is from an authorized sender. Updating DKIM records ensures that emails are properly signed and authenticated.

D. DNSSEC (Domain Name System Security Extensions): DNSSEC adds security to DNS by enabling DNS responses to be verified. While important for DNS security, it does not directly address the issue of emails being marked as spam.

E. SASC: This is not a relevant standard for this scenario.

F. SAN (Subject Alternative Name): SAN is used in SSL/TLS certificates for securing multiple domain names, not for email delivery issues.

G. SOA (Start of Authority): SOA records are used for DNS zone administration and do not directly impact email deliverability.

H. MX (Mail Exchange): MX records specify the mail servers responsible for receiving email on behalf of a domain. While important, the primary issue here is the authentication of outgoing emails, which is handled by SPF, DKIM, and DMARC.

References:

CompTIA Security+ Study Guide

RFC 7208 (SPF), RFC 6376 (DKIM), and RFC 7489 (DMARC)

NIST SP 800-45, "Guidelines on Electronic Mail Security"

To ensure always-on VPN access is enabled and restricted to company assets, the network engineer needs to generate device certificates using the specific template settings required for the company's VPN solution. These certificates ensure that only authorized devices can establish a VPN connection.

Why Device Certificates are Necessary:

Authentication: Device certificates authenticate company assets, ensuring that only authorized devices can access the VPN.

Security: Certificates provide a higher level of security compared to username and password combinations, reducing the risk of unauthorized access.

Compliance: Certificates help in meeting security policies and compliance requirements by ensuring that only managed devices can connect to the corporate network.

Other options do not provide the same level of control and security for always-on VPN access:

B. Modify signing certificates for IKE version 2: While important for VPN protocols, it does not address device-specific authentication.

C. Create a wildcard certificate: This is not suitable for device-specific authentication and could introduce security risks.

D. Add the VPN hostname as a SAN entry: This is more related to certificate management and does not ensure device-specific authentication.

References:

CompTIA SecurityX Study Guide

"Device Certificates for VPN Access," Cisco Documentation

NIST Special Publication 800-77, "Guide to IPsec VPNs"

The reported issues suggest problems related to network connectivity, remote access, and certificate management:

A. Review VPN throughput: Connectivity issues and the inability to download applications while working remotely may be due to VPN bandwidth or performance issues. Reviewing and optimizing VPN throughput can help resolve these problems by ensuring that remote users have adequate bandwidth for accessing corporate resources.

F. Validate MDM asset compliance: Mobile Device Management (MDM) systems ensure that mobile endpoints comply with corporate security policies. Validating MDM compliance can help address issues related to the inability to download applications and certificate errors, as non-compliant devices might be blocked from accessing certain resources.

B. Check IPS rules: While important for security, IPS rules are less likely to directly address the connectivity and certificate issues described.

C. Restore static content on the CDN: This action is related to content delivery but does not address VPN or certificate-related issues.

D. Enable secure authentication using NAC: Network Access Control (NAC) enhances security but does not directly address the specific issues described.

E. Implement advanced WAF rules: Web Application Firewalls protect web applications but do not address VPN throughput or mobile device compliance.

References:

CompTIA Security+ Study Guide

NIST SP 800-77, "Guide to IPsec VPNs"

CIS Controls, "Control 11: Secure Configuration for Network Devices"