Free Practice Questions for CompTIA CAS-004 Exam

The methods that can be used to protect user internet privacy, to ensure the connection is encrypted, and to keep user activity hidden are proxy and MAC address randomization. A proxy is a server that acts as an intermediary between a user and the internet, hiding the user’s IP address and location from websites and other online services. A proxy can also encrypt the connection between the user and the proxy server, preventing anyone from snooping on the user’s traffic. MAC address randomization is a feature that changes the MAC address of a mobile device periodically or when connecting to different networks. A MAC address is a unique identifier of a network interface that can be used to track the device’s location and activity. MAC address randomization can help protect the user’s privacy by making it harder for third parties to link the device to a specific user or network. Verified References:

https://www.techtarget.com/searchsecurity/definition/proxy-server

https://www.techtarget.com/searchnetworking/definition/MAC-address-randomization

https://www.techtarget.com/searchsecurity/definition/MAC-address-Media-Access-Control-address

A content delivery network (CDN) is a geographically distributed network of servers that can cache content close to end users, allowing for faster and more efficient delivery of web content, such as images, videos, and streaming media. A CDN can also handle an increase in customer demand of resources, provide high-quality streaming media, and create a user-friendly interface by reducing latency and bandwidth consumption. A CDN can also improve the security and availability of the website by mitigating DDoS attacks and providing redundancy. Verified References:

https://www.cloudflare.com/learning/cdn/what-is-a-cdn/

https://learn.microsoft.com/en-us/azure/cdn/cdn-overview

https://en.wikipedia.org/wiki/Content_delivery_network

A risk associated with SDN is the expanded attack surface that it introduces. SDN is a network architecture that decouples the control plane from the data plane, allowing centralized and programmable management of network devices and traffic. However, this also exposes new attack vectors and vulnerabilities that can compromise the security and performance of the network. For example, an attacker can target the SDN controller, which is the core component that communicates with and controls the network devices. A successful attack on the SDN controller can result in denial of service, unauthorized access, data leakage, or network hijacking. An attacker can also exploit the communication channels between the SDN controller and the network devices, such as the OpenFlow protocol, to intercept, modify, or inject malicious messages or commands. Additionally, an attacker can leverage malicious or compromised applications that run on top of the SDN controller to manipulate or disrupt the network behavior. Verified References:

https://www.isaca.org/resources/isaca-journal/issues/2016/volume-4/benefits-and-the-security-risk-of-software-defined-networking

https://link.springer.com/article/10.1007/s40860-022-00171-8

OPC (Open Platform Communications) and Modbus are two common protocols used for industrial control systems (ICS). OPC is a standard that allows different devices and applicationsto exchange data in a vendor-neutral way. Modbus is a serial communication protocol that enables devices to send and receive commands and data over a network. Modbus has two variants: Modbus TCP/IP, which uses TCP port 502 for communication, and Modbus RTU/ASCII, which uses serial ports.

To allow an OPC server to communicate with a Modbus server that is controlling electrical relays, the security engineer should recommend restricting inbound traffic so that only the OPC server is permitted to reach the Modbus server on port 502. This configuration would:

Permit the OPC server to send commands and data to the Modbus server using Modbus TCP/IP protocol over port 502.

Limit operational disruptions, by preventing unauthorized or malicious access to the Modbus server from other sources.

Due to the limitations within the Modbus protocol, such as lack of encryption and authentication, restricting inbound traffic is a necessary security measure to protect the integrity and availability of the ICS.

The three metric groups that are needed to calculate CVSS scores are Base, Temporal, and Environmental. The Base metrics represent the intrinsic characteristics of a vulnerability that are constant over time and across user environments. The Temporal metrics represent the characteristics of a vulnerability that may change over time but not across user environments. The Environmental metrics represent the characteristics of a vulnerability that are relevant and unique to a particular user’s environment. Verified References:

https://nvd.nist.gov/vuln-metrics/cvss

https://www.first.org/cvss/specification-document