ISA-IEC-62443 ISA/IEC 62443 Cybersecurity Fundamentals Specialist Questions and Answers

According to the ISA/IEC 62443-3-2 standard, implementing countermeasures is one of the steps in the security risk assessment for system design. The standard defines a comprehensive set of engineering measures to guide organizations through the process of assessing the risk of a particular industrial automation and control system (IACS) and identifying and applying security countermeasures to reduce that risk to tolerable levels. The standard recommends the following steps for implementing countermeasures:

• Establish the risk tolerance: This step involves determining the acceptable level of risk for the organization and the system under consideration, based on the business objectives, legal and regulatory requirements, and stakeholder expectations. The risk tolerance can be expressed as a target security level (SL-T) for each zone or conduit in the system.
• Select common countermeasures: This step involves selecting the appropriate security countermeasures for each zone or conduit, based on the SL-T and the existing security level (SL-A) of the system. The standard provides a list of common countermeasures for each security level, covering the domains of physical security, network security, system security, and application security. The selected countermeasures should be documented and justified in the security risk assessment report. References: ISA/IEC 62443 Cybersecurity Series Designated as IEC Horizontal Standards, Cybersecurity Risk Assessment According to ISA/IEC 62443-3-2

"A common pitfall is to attempt to initiate a CSMS program without at least a high-level rationale that relates cyber security to the specific organization and its mission."

A CSMS program is a Cybersecurity Management System program that follows the IEC 62443 standards for securing industrial control systems (ICS)1. A common pitfall when initiating a CSMS program is D. Immediate jump into detailed risk assessment. This is because a detailed risk assessment requires a clear definition of the system under consideration (SuC), the allocation of IACS assets to zones and conduits, and the identification of threats, vulnerabilities, and consequences for each zone and conduit2. These steps are part of the assess phase of the CSMS program, which is the first phase of the security program development process2. However, before starting the assess phase, it is important to have the management team’s support to ensure the CSMS program will have sufficient financial and organizational resources to implement necessary actions2. Therefore, jumping into detailed risk assessment without having the management buy-in is a common mistake that can jeopardize the success of the CSMS program.

A security conduit is a logical or physical grouping of communication channels connecting two or more zones that share common security requirements1. A zone is a grouping of systems and components based on their functional, logical, and physical relationship that share common security requirements1. Therefore, a security conduit consists of assets that enable or facilitatecommunication between zones, such as wiring, routers, switches, and network management devices. Controllers, sensors, transmitters, and final control elements are examples of assets that belong to a zone, not a conduit. Ferrous, thickwall, and threaded conduit including raceways are physical structures that may enclose or protect wiring, but they are not part of the communication channels themselves. Power lines, cabinet enclosures, and protective grounds are also not part of the communication channels, but rather provide power or protection to the assets in a zone or a conduit. References: 1: Key Concepts of ISA/IEC 62443: Zones & Security Levels | Dragos

The Modbus Application Protocol is a messaging protocol that provides client/server communication between devices connected on different types of buses or networks. It is positioned at level 7 of the OSI model, which is the application layer. The application layer is the highest level of the OSI model and defines the rules and formats for data exchange between applications. The Modbus Application Protocol is independent of the underlying communication layers and can be implemented using different transport protocols, such as TCP/IP, serial, or Modbus Plus. The Modbus Application Protocoldefines the function codes, data formats, and error codes for Modbus transactions123 References:

• MODBUS APPLICATION PROTOCOL SPECIFICATION V1
• Modbus - Wikipedia
• Overview of Modbus — EPICS support for Modbus - GitHub Pages

According to the ISA/IEC 62443 Cybersecurity Fundamentals, the risk matrix is a tool used to assess the risk of a particular event. The risk matrix is divided into three categories: likelihood, consequence, and risk. The likelihood is the probability that an event will occur, the consequence is the impact that the event will have, and the risk is the combination of the two. In this case, the risk of a medium likelihood event with high consequence is a high risk, as shown by the red cell in the matrix. References:

• ISA/IEC 62443 Cybersecurity Fundamentals
• [ISA/IEC 62443 Cybersecurity Certificate Program]
• [Cybersecurity Library]
• [Using the ISA/IEC 62443 Standard to Secure Your Control Systems]

API 1164 is an industry sector-specific standard that provides guidance on the cybersecurity of pipeline supervisory control and data acquisition (SCADA) systems. API stands for American Petroleum Institute, which is the largest U.S. trade association for the oil and natural gas industry. API 1164 was first published in 2004 and revised in 2009 and 2021. The latest version of the standard aligns with the ISA/IEC 62443 series of standards and incorporates the concepts of security levels, zones, and conduits. API 1164 covers the security lifecycle of pipeline SCADA systems, from risk assessment and policy development to implementation and maintenance. The standard also defines roles and responsibilities, security requirements, security controls, and security assessment methods for pipeline SCADA systems.

References:

• API 1164: Pipeline SCADA Security, Fourth Edition, September 2021
• ISA/IEC 62443 Cybersecurity Fundamentals Specialist Study Guide, Section 2.2.2, Industry Sector-Specific Standards
• ISA/IEC 62443 Cybersecurity Fundamentals Specialist Exam Specification, Section 2.2.2, Industry Sector-Specific Standards

The ISA/IEC 62443 series of standards is divided into four main parts, each covering a different aspect of industrial automation and control systems (IACS) cybersecurity1:

• Part 1: Terminology, Concepts, and Models
• Part 2: Policies and Procedures
• Part 3: System Requirements
• Part 4: Component Requirements The part 4 of the series focuses on the requirements for the secure development and maintenance of products that are used in IACS, such as controllers, sensors, actuators, network devices, software applications, and cloud services. The part 4 consists of two standards1:

Application whitelisting (AWL) is a technique that allows only authorized applications to run on a system, and blocks any unauthorized or malicious code from executing. AWL is one of the most effective methods for preventing malware infections and reducing the attack surface of a system. AWL can be implemented at different levels, such as the operating system, the network, or the application itself. AWL is especially useful forindustrial automation and control systems (IACS), which often run on legacy or proprietary platforms that are not compatible with traditional antivirus software or other security solutions. AWL can also help protect IACS from zero-day attacks, which exploit unknown vulnerabilities that have not been patched or detected by security vendors. AWL is recommended by the ISA/IEC 62443 standards as a key component of malicious code protection for IACS. According to the standards, AWL should be applied to all IACS components that support it, and should be configured and maintained according to the security policies and procedures of the organization. AWL should also be complemented by other security measures, such as network segmentation, zones and conduits, and patch management, to provide a defense-in-depth approach to IACS security. References:

• ISA/IEC 62443-3-3:2013, System security requirements and security levels, Section 5.2.3.41
• ISA/IEC 62443-2-1:2010, Establishing an industrial automation and control systems security program, Section 4.3.3.6.42
• ISA/IEC 62443-4-2:2019, Technical security requirements for IACS components, Section 4.2.3.43
• ISA/IEC 62443-3-2:2020, Security risk assessment for system design, Section 7.3.3.44
• ISA/IEC 62443-4-1:2018, Product development requirements, Section 5.2.3.45

 Access control is the process of granting or denying specific requests to obtain and use information and related information processing services. It is one of the foundational requirements (FRs) of the ISA/IEC 62443 standards for securing industrial automation and control systems (IACSs). According to the ISA/IEC 62443-3-3 standard, access control includes the following system requirements (SRs):

• SR 1.1: Identification and authentication control
• SR 1.2: Use control
• SR 1.3: System integrity
• SR 1.4: Data confidentiality
• SR 1.5: Restricted data flow
• SR 1.6: Timely response to events
• SR 1.7: Resource availability

Among these SRs, the ones that are most related to the critical variables of account management and password strength are SR 1.1 and SR 1.2. SR 1.1 requires that the IACS shall provide the capability to uniquely identify and authenticate all users, processes, and devices that attempt to establish a logical connection to the system. This means that the IACS should have a robust account management system that can create, modify, delete, and monitor user accounts and their privileges. It also means that the IACS should enforce strong password policies that can prevent unauthorized access or compromise of user credentials. Password strength refers to the level of difficulty for an attacker to guess or crack a password. It depends on factors such as length, complexity, randomness, and uniqueness of the password.

SR 1.2 requires that the IACS shall provide the capability to enforce the use of logical connections in accordance with the security policy of the organization. This means that the IACS should have a mechanism to control the access rights and permissions of users, processes, and devices based on their roles, responsibilities, and needs. It also means that the IACS should have a mechanism to audit and log the activities and events related to access control, such as successful or failed login attempts, password changes, privilege escalations, or unauthorized actions.

Therefore, account management and password strength are the critical variables related to access control, as they directly affect the identification, authentication, and authorization of users, processes, and devices in 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 Cybersecurity Fundamentals Specialist Certificate Program2
• ISA/IEC 62443 Cybersecurity Library3
• Using the ISA/IEC 62443 Standards to Secure Your Control Systems4

IT systems and IACS have different security priorities, requirements, and challenges. According to the ISA/IEC 62443 standards, the security priority for IT systems is confidentiality, which means protecting the data from unauthorized access or disclosure. The security priority for IACS is integrity, which means ensuring the accuracy and consistency of the data and the functionality of the system. A loss of integrity in an IACS can have severe consequences, such as physical damage, environmental harm, or human injury. Therefore, IACS cybersecurity must address safety issues, which are not typically considered in IT security. Safety is the ability of the system to prevent or mitigate hazardous events that can cause harm to people, property, or the environment. The ISA/IEC 62443 standards provide guidance and best practices for ensuring the safety and security of IACS, as well as the availability and reliability of the system. Availability is the ability of the system to perform its intended function when required, and reliability is the ability of the system to perform its intended function without failure. These properties are also important for IT systems, but they may have different trade-offs and implications for IACS. For example, an IACS may have stricter performance and availability requirements than an IT system, as a delay or disruption in the IACS operation can affect the industrial process and its outcomes. Additionally, an IACS may have longer equipment lifetimes and less frequent maintenance windows than an IT system, which can make patching and updating more difficult and risky. Furthermore, an IACS may use different technologies and architectures than an IT system, such as legacy devices, proprietary protocols, or specialized hardware. These factors can create compatibility and interoperability issues, as well as increase the attack surface and complexity of the IACS. Therefore, IT security solutions and practices may not be sufficient or suitable for IACS, and they may need to be adapted or supplemented by IACS-specific security measures. The ISA/IEC 62443 standards address these differences and provide a comprehensive framework for securing IACS throughout their lifecycle.

References: 1: Security of Industrial Automation and Control Systems - ISAGCA 2: ISA/IEC 62443 Series of Standards - ISA 3: ISA/IEC 62443 Series of Standards | ISAGCA 4: Securing IACS based on ISA/IEC 62443 – Part 1: The Big Picture

• The key differences between IT (Information Technology) systems and IACS (Industrial Automation and Control Systems) are centered on their primary security objectives and operational requirements:
• Option A: The IACS security priority is integrity. This is crucial because any unauthorized modification of data or commands can lead to severe operational disruptions and safety hazards.
• Option C: IACS cybersecurity must address safety issues. Safety is a primary concern in IACS environments where process disruptions or malfunctions can result in harm to human operators or damage to equipment. The primary security priority in traditional IT systems is often confidentiality, not availability as stated in Option B, and routers are commonly used in IACS networks, contrary to Option D.

Patch management is the process of applying software updates to fix security vulnerabilities, improve functionality, or enhance performance. Patch management is an essential part of cybersecurity, as unpatched systems can be exploited by malicious actors. However, patch management for industrial automation and control systems (IACS) is more challenging than for business systems, because patching a live automation system can create safety risks. According to the ISA/IEC 62443 standards, patching an IACS may have the following potential impacts1:

• Patching may introduce new vulnerabilities or errors that compromise the availability, integrity, or confidentiality of the IACS.
• Patching may affect the functionality or performance of the IACS, causing unexpected or undesired behavior, such as process shutdowns, slowdowns, or failures.
• Patching may require downtime or reduced operation of the IACS, which may affect production, quality, or profitability.
• Patching may require additional resources, such as personnel, equipment, or testing facilities, which may not be readily available or affordable.

Therefore, patch management for IACS requires careful planning, testing, and validation before applying patches to the operational environment. The ISA/IEC 62443 standards provide guidance and best practices for patch management in the IACS environment, such as1:

• Establishing a patch management program that defines roles, responsibilities, policies, and procedures for patching IACS components and systems.
• Identifying and prioritizing the IACS assets that need patching, based on their criticality, vulnerability, and risk level.
• Evaluating and verifying the patches for compatibility, functionality, and security before applying them to the IACS.
• Implementing and documenting the patching process, including backup, recovery, and rollback procedures, in case of patch failure or adverse effects.
• Monitoring and auditing the patching activities and outcomes, and reporting any issues or incidents.

References: 1: ISA TR62443-2-3 - Security for industrial automation and control systems, Part 2-3: Patch management in the IACS environment

Patches are software updates that fix bugs, vulnerabilities, or improve performance or functionality. Patches are important for maintaining the security and reliability of an IACS environment, but they also pose some challenges and risks. Applying patches in an IACS environment is not as simple as in an IT environment, because patches may affect the availability, integrity, or safety of the IACS. Therefore, patches should not be applied blindly or automatically, but based on the organization’s risk assessment. The risk assessment should consider the following factors: 1

• The severity and likelihood of the vulnerability that the patch addresses
• The impact of the patch on the IACS functionality and performance
• The compatibility of the patch with the IACS components and configuration
• The availability of a backup or recovery plan in case the patch fails or causes problems
• The testing and validation of the patch before applying it to the production system
• The communication and coordination with the stakeholders involved in the patching process
• The documentation and auditing of the patching activities and results References: ISA TR62443-2-3 - Security for industrial automation and control systems, Part 2-3: Patch management in the IACS environment

 Modbus over Ethernet, also known as Modbus/TCP, is a protocol that encapsulates the Modbus/RTU data string inside the data section of the TCP frame. It then sets up a client/server exchange between nodes, using TCP/IP addressing to establish connections1. This makes it easy to manage in a firewall, because the firewall can filter the traffic based on the source and destination IP addresses and the TCP port number. The default TCP port for Modbus/TCP is 502, but it can be changed if needed. Modbus/TCP does not use any other ports or protocols, so the firewall rules can be simple and specific. References:

• 8: Open Modbus/TCP Specification, RTA Automation, 2010.
• [9]: Modbus Application Protocol Specification V1.1b3, Modbus Organization, 2012.

The ISASecure certification program, aligned with the ISA/IEC 62443 standards, defines three distinct security levels that categorize the robustness of industrial control systems against known cybersecurity threats. These levels are designed to provide a scalable approach to securing industrial automation and control systems, with each level offering a higher degree of security. The levels are typically identified as SL1 (Security Level 1), SL2 (Security Level 2), and SL3 (Security Level 3), each addressing increasingly stringent security capabilities and resilience against cyber attacks.

According to the ISA/IEC 62443-2-1 standard, a review of the CSMS should be triggered by any changes that affect the cybersecurity risk of the industrial automation and control system (IACS), such as new technical controls, organizational restructuring, or security incidents1. Budgeting is not a trigger for CSMS review, unless it impacts the cybersecurity risk level or the CSMS itself2. References: 1: ISA/IEC 62443-2-1:2010, Section 4.3.3.3 2: A Practical Approach to Adopting the IEC 62443 Standards, ISAGCA Blog3

Monitoring and improving a Cybersecurity Management System (CSMS) as per ISA/IEC 62443 standards involves several key activities that ensure the system remains effective and responsive to emerging threats. Two critical elements of this ongoing process are:

• A. Increase in staff training and security awareness:Regular training and increasing security awareness among staff are vital to maintaining a secure operating environment. This proactive measure helps in reducing human error and enhancing the ability to respond effectively to cybersecurity incidents.
• D. Review of system logs and other key data files:Continuous review and analysis of system logs and other relevant data files are essential for detecting, investigating, and responding to potential security incidents. This monitoring helps in identifying anomalies that may indicate a security breach or operational issues needing attention.

ISO/IEC 15408, also known as the Common Criteria for Information Technology Security Evaluation, is an international standard that provides a framework for evaluating the security of IT products and systems. The purpose of the standard is to define a common set of requirements for the security functions and assurance measures of IT products and systems, and to establish a common methodology for conducting security evaluations. The standard allows users to specify their security needs and expectations in a Security Target (ST), which may be based on one or more Protection Profiles (PPs)that define security requirements for a class of products or systems. Vendors can then implement or claim compliance with the ST or PPs, and have their products or systems evaluated by independent testing laboratories against the security criteria defined in the standard. The standard also defines a scale of Evaluation Assurance Levels (EALs) that indicate the degree of confidence in the security of the evaluated product or system. The standard is intended to facilitate the development, procurement, and use of secure IT products and systems, and to promote the recognition and acceptance of evaluation results across different countries and regions. References:

• ISO/IEC 15408-1:2009 - Common Criteria Evaluation for IT Security - Nemko1
• Common Criteria - Wikipedia2
• ISO/IEC Standard 15408 — ENISA3

 ISA-TR62443-2-3 is the technical report that describes the requirements for asset owners and industrial automation and control system (IACS) product suppliers that have established and are now maintaining an IACS patch management program. Patch management is the process of applying software updates to fix vulnerabilities, bugs, or performance issues in the IACS components. Patch management is an essential part of maintaining the security and reliability of the IACS environment. The technical report provides guidance on how to establish a patch management policy, how to assess the impact and risk of patches, how to test and deploy patches, and how to monitor and audit the patch management process. References: 1, 2, 3

Role-based access control (RBAC) is a method of restricting access to resources based on the roles of individual users within an organization. RBAC assigns permissions and responsibilities to roles, rather than to individual users, and then assigns users to those roles. This way, users can only perform the actions that are relevant and necessary for their role, and not access or modify any other resources that are beyond their scope of authority. RBAC is one of the security countermeasures that can be implemented in a defense-in-depth strategy, which is a layered approach to protect industrial automation and control systems (IACS) from cyber threats. RBAC can help prevent unauthorized access, misuse, or sabotage of IACS resources, as well as reduce the risk of human error or insider attacks.

References:

• ISA/IEC 62443-3-3:2013, Security for industrial automation and control systems - Part 3-3: System security requirements and security levels, Clause 5.3.2.11
• ISA/IEC 62443-2-1:2010, Security for industrial automation and control systems - Part 2-1: Establishing an industrial automation and control systems security program, Clause 6.2.2.32
• ISA/IEC 62443-4-1:2018, Security for industrial automation and control systems - Part 4-1: Product security development life-cycle requirements, Clause 5.2.3.23
• ISA/IEC 62443-4-2:2019, Security for industrial automation and control systems - Part 4-2: Technical security requirements for IACS components, Clause 4.2.3.24

 According to the IEC 62443 standard, a capability security level (SL-C) is defined as “the security level that a component or system is capable of meeting when it is properly configured and protected by an appropriate set of security countermeasures” 1. A component or system can have different SL-Cs for different security requirements, depending on its design and implementation. The SL-C is determined by testing the component or system against a set of security test cases that correspond to the security requirements. The SL-C is not dependent on the actual operational environment orconfiguration of the component or system, but rather on its inherent capabilities. References:

• IEC 62443 - Wikipedia

According to the ISA/IEC 62443 standards, the level of risk an organization is willing to tolerate is determined by the management, as they are responsible for defining the business and risk objectives, as well as the security policies and procedures for the organization. The management also has the authority to allocate the necessary resources and assign the roles and responsibilities for implementing and maintaining the security program. The legal, operations, and safety departments may provide input and feedback to the management, but they do not have the final say in determining the risk tolerance level. References: ISA/IEC 62443-2-1:2010 - Establishing an industrial automation and control systems security program, section 4.2.1.

According to the ISA/IEC 62443-3-2 standard, a security zone is a grouping of systems and components based on their functional, logical, and physical relationship that share common security requirements. The primary objective of defining a security zone is to apply a consistent level of protection to the assets within the zone, based on their criticality and risk assessment. A security zone may contain assets from different vendors, different levels in the Purdue model, or different physical locations, as long as they have the same security requirements. A security zone may also be subdivided into subzones, if there are different security requirements within the zone. A conduit is a logical or physical grouping of communication channels connecting two or more zones that share common security requirements.

References:

• ISA/IEC 62443-3-2:2020, Security for industrial automation and control systems - Part 3-2: Security risk assessment for system design, Clause 4.3.21
• ISA/IEC 62443-1-1:2009, Security for industrial automation and control systems - Part 1-1: Terminology, concepts and models, Clause 3.2.42

In ANSI/ISA-99.00.01:2007, which is part of the ISA/IEC 62443 standards, electronic security encompasses both the technical and human aspects of cybersecurity within industrial automated and control systems (IACS). Option B correctly highlights components such as computers, networks, operating systems, applications, and other programmable configurable components which are intrinsic to the system's electronic security framework. Option C is also correct as it includes the personnel, policies, andprocedures which play a crucial role in securing these systems. This emphasizes that security is not only about the technological solutions but also about managing human elements and organizational processes effectively.ISA/IEC 62443 Cybersecurity Fundamentals References:

• ISA/IEC 62443 standards focus on the holistic nature of security which is clearly supported by including both the technological (Option B) and human elements (Option C) in the definition of electronic security.