Pass the ISA Cybersecurity ISA-IEC-62443 Questions and answers with CertsForce

The ISA-99/IEC 62443 standards for industrial automation and control systems security categorize network and system components into different levels based on their operational context. The correct name from the provided options for one of these levels is Level 3: Operations Management. This level typically encompasses systems that manage production control systems, including batch management, production scheduling, and overall factory operations. The other levels listed, such as Supervisory Control and Process, refer to different aspects of the system but are not named correctly in the options provided. Level 1 is correctly referred to as "Basic Control," and Level 4 should be "Business Logistics" instead of "Process."

ISA/IEC 62443 defines “defense in depth” as a layered approach to security. This can be accomplished by implementing zones within zones (sometimes called subzones), where each zone or subzone provides an additional security barrier or control layer. This segmentation restricts an attacker's ability to move laterally and ensures that compromise of one zone does not automatically result in compromise of the entire system.

The selection of countermeasures is driven by the output from a risk assessment, which identifies the risks and their associated likelihood and consequences for each zone and conduit in the industrial automation and control system (IACS). The risk assessment also determines the target security level (SL-T) for each zone and conduit, which represents the desired level of protection against the identified threats. The countermeasures are then selected based on the SL-T and the existing security level (SL-A) of the zone and conduit, as well as the cost and feasibility of implementation. The countermeasures should aim to reduce the risk to an acceptable level by increasing the SL-A to meet or exceed the SL-T. References: ISA/IEC 62443-3-2:2018 - Security risk assessment for system design, ISA/IEC 62443-3-3:2013 - System security requirements and security levels, ISA/IEC 62443 Cybersecurity Fundamentals Specialist Training Course

A Local Area Network (LAN) is not a strategy for deploying a Wide Area Network (WAN). WAN deployment strategies include using the public Internet, private enterprise WANs, or carrier-managed WANs. LANs, by definition, serve local, not wide-area, connectivity. ISA/IEC 62443 standards refer to different strategies for extending network communications over broader geographic regions, but do not classify LAN as a WAN deployment option.

The ISASecure Integrated Threat Analysis (ITA) Program is a certification scheme that certifies off-the-shelf automation and control systems to the ISA/IEC 62443 series of standards1. The ITA Program consists of three main components2:

Software Development Security Assurance (SDSA): This component evaluates the security lifecycle and practices of the product supplier, such as security requirements, design, implementation, verification, and maintenance. The SDSA certification is based on the ISA/IEC 62443-4-1 standard.

Functional Security Assessment (FSA): This component verifies the security functions and features implemented in the product, such as identification and authentication, access control, encryption, audit logging, and security management. The FSA certification is based on the ISA/IEC 62443-4-2 standard.

Communications Robustness Testing (CRT): This component tests the resilience of the product against network attacks, such as denial-of-service, fuzzing, spoofing, and replay. The CRT certification is based on the ISA/IEC 62443-4-2 and ISA/IEC 62443-3-3 standards .

 MODBUS/TCP is the name of the protocol that implements serial Modbus over Ethernet. MODBUS/TCP is a variant of the Modbus protocol that uses the Transmission Control Protocol (TCP) as the transport layer to encapsulate Modbus messages and send them over Ethernet networks. MODBUS/TCP preserves the Modbus application layer and data model, which means that serial Modbus devices can communicate with MODBUS/TCP devices through a gateway or a converter. MODBUS/TCP is widely used in industrial automation and control systems, as it offers high performance, interoperability, and compatibility with existing Modbus devices. References: ISA/IEC 62443 Cybersecurity Fundamentals Specialist Study Guide, Section 3.1.21; MODBUS Application Protocol Specification V1.1b3, Section 1.1

The ISA/IEC 62443 standards are divided into four main groups: General, Policies and Procedures, System, and Component. The first group, “General,” includes foundational standards and technical reports that provide essential concepts, models, terminology, and overall guidance for the rest of the series. This includes parts such as 62443-1-1 (concepts and models), 1-2 (glossary), 1-3 (metrics), and 1-4 (security lifecycle and use cases).

The Presentation layer (Layer 6) of the OSI model is responsible for data format conversion (such as character set translation) and encryption/decryption of messages. This layer ensures that data sent from the application layer of one system can be read by the application layer of another, regardless of differences in data representation.

Multiuser accounts and shared passwords are accounts and passwords that are used by more than one person to access a system or a resource. They inherently carry the risk of unauthorized access, which means that someone who is not authorized or intended to use the account or password can gain access to the system or resource, and potentially compromise its confidentiality, integrity, or availability. For example, if a multiuser account and password are shared among several operators of an industrial automation and control system (IACS), an attacker who obtains the password can use the account to access the IACS and perform malicious actions, such as changing the system settings, deleting data, or disrupting the process. Multiuser accounts and shared passwords also make it difficult to track and audit the activities of individual users, and to enforce the principle of least privilege, which states that users should only have the minimum level of access required to perform their tasks. Therefore, the ISA/IEC 62443 standards recommend avoiding the use of multiuser accounts and shared passwords, and instead using individual accounts and strong passwords for each user, and implementing authentication and authorization mechanisms to control the access to the IACS. References:

ISA/IEC 62443-3-3:2013 - Security for industrial automation and control systems - Part 3-3: System security requirements and security levels1

ISA/IEC 62443-2-1:2009 - Security for industrial automation and control systems - Part 2-1: Establishing an industrial automation and control systems security program2

ISA/IEC 62443 Cybersecurity Fundamentals Specialist Training Course3

Shared passwords and multiuser accounts pose specific risks, notably unauthorized access and privilege escalation. In ISA/IEC 62443's framework, these practices are discouraged because they complicate the attribution of actions to individual users and increase the likelihood that accounts can be used beyond their intended scope. Unauthorized access occurs when individuals exploit the shared nature of an account to gain entry to systems or data that they should not access. Privilege escalation can happen when users leverage shared accounts to perform actions at higher permission levels than those assigned to their personal accounts. Conversely, buffer overflows and race conditions are types of vulnerabilities or programming errors, not directly associated with the risks of multiuser accounts or shared passwords.

The four documents classified under the General category of ISA/IEC 62443 are:

Part 1-1: Terminology, concepts, and models

Part 1-2: Master glossary of terms and definitions

Part 1-3: System security conformance metrics