ECCouncil ICS-SCADA Cyber Security Practice Test - Questions Answers, Page 7

The protocol number 6 represents TCP (Transmission Control Protocol) in the Internet Protocol suite. TCP is a core protocol of the Internet Protocol suite and operates at the transport layer, providing reliable, ordered, and error-checked delivery of a stream of bytes between applications running on hosts communicating via an IP network.

Reference:

RFC 793, 'Transmission Control Protocol,' which specifies the detailed operation of TCP.

Industrial Control Systems (ICS) and SCADA networks typically operate in environments where the available bandwidth is limited. They are often characterized by:

Low processing threshold: ICS/SCADA devices generally have limited processing capabilities due to their specialized and often legacy nature.

Legacy systems: Many ICS/SCADA systems include older technology that might not support newer security protocols or high-speed data transfer.

Weak network stack: These systems may have incomplete or less robust network stacks that can be susceptible to specific types of network attacks.

High bandwidth networks are not typical of ICS/SCADA environments, as these systems do not usually require or support high-speed data transmission due to their operational requirements and the older technology often used in such environments.

Reference

'Navigating the Challenges of Industrial Control Systems,' by ISA-99 Industrial Automation and Control Systems Security.

'Cybersecurity for Industrial Control Systems,' by the Department of Homeland Security.

The Common Vulnerability Scoring System (CVSS) uses several metrics to assess the severity of vulnerabilities. Among them, the Temporal metric group specifically reflects the exploit quotient of a vulnerability.

Temporal metrics consider factors that change over time after a vulnerability is initially assessed. These include:

Exploit Code Maturity: This assesses the likelihood of the vulnerability being exploited based on the availability and maturity of exploit code.

Remediation Level: The level of remediation available for the vulnerability, which influences the ease of mitigation.

Report Confidence: This metric measures the reliability of the reports about the vulnerability.

These temporal factors directly affect the exploitability and potential threat posed by a vulnerability, adjusting the base score to provide a more current view of the risk.

Reference

Common Vulnerability Scoring System v3.1: User Guide.

'Understanding CVSS,' by FIRST (Forum of Incident Response and Security Teams).

Modbus TCP is a variant of the Modbus family of simple, networked protocols aimed at industrial automation applications. Unlike the original Modbus protocol, which runs over serial links, Modbus TCP runs over TCP/IP networks.

Port 502 is the standard TCP port used for Modbus TCP communications. This port is designated for Modbus messages encapsulated in a TCP/IP wrapper, facilitating communication between Modbus devices and management systems over an IP network.

Knowing the correct port number is crucial for network configuration, security settings, and troubleshooting communications within a Modbus-enabled ICS/SCADA environment.

Reference

Modbus Organization, 'MODBUS Application Protocol Specification V1.1b3'.

'Modbus TCP/IP -- A Comprehensive Network protocol,' by Schneider Electric.

In the context of network security policies, a 'Paranoid' stance typically means adopting a default-deny posture. This security approach is one of the most restrictive, where all access is blocked unless explicitly allowed.

A default deny strategy is considered best practice for securing highly sensitive environments, as it minimizes the risk of unauthorized access and reduces the attack surface.

This approach contrasts with more open stances such as Permissive or Promiscuous, which are less restrictive and generally allow more traffic by default.

Reference

'Network Security: Policies and Guidelines for Effective Network Management,' by Jonathan Gossels.

'Best Practices for Implementing a Security Awareness Program,' by Kaspersky Lab.

In the configuration of Microsoft Windows Firewall with Advanced Security, you can define IPsec rules as part of your security policy. Typically, these rules can be organized into four main categories: Allow connection, Block connection, Allow if secure (which can specify encryption or authentication requirements), and Custom. While the interface and features can vary slightly between Windows versions, four fundamental types of rules regarding how traffic is handled are commonly supported.

Reference:

Microsoft documentation, 'Windows Firewall with Advanced Security'.

In ICS/SCADA systems, the typical priority hierarchy of the IT Security Model components places Availability and Integrity above Confidentiality. This prioritization is due to the critical nature of operational continuity and data accuracy in industrial control systems, where system downtime or incorrect data can lead to significant operational disruptions or safety issues. Confidentiality, while important, is often considered of lesser priority compared to ensuring systems are operational (Availability) and data is accurate (Integrity).

Reference:

National Institute of Standards and Technology (NIST), 'Guide to Industrial Control Systems (ICS) Security'.

In the Modbus protocol, the function code is used to tell the slave device what kind of action to perform, such as reading or writing data.

Modbus function codes specify the type of operation to be performed on the registers. For example, function code 03 is used to read holding registers, and function code 06 is used to write a single register.

Each function code is a single byte in size and is positioned at the start of the PDU (Protocol Data Unit) in the Modbus message structure, directly influencing how the slave interprets and executes the request.

Reference

'Modbus Application Protocol Specification V1.1b,' Modbus Organization.

'The Modbus Protocol Explained,' by Schneider Electric.

In ICS/SCADA systems, the highest priority typically is Availability, due to the critical nature of the services and infrastructures they support. These systems often control vital processes in industries like energy, water treatment, and manufacturing. Any downtime can lead to significant disruptions, safety hazards, or economic losses. Thus, ensuring that systems are operational and accessible is a primary security focus in the context of ICS/SCADA security.

Reference:

National Institute of Standards and Technology (NIST), 'Guide to Industrial Control Systems (ICS) Security'.