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

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

Security zones are logical groupings of assets that share common security requirements based on factors such as criticality, consequence, vulnerability, and threat. Security zones are used to apply the principle of defense in depth, which means creating multiple layers of protection to prevent or mitigate cyberattacks. By creating security zones, asset owners can isolate the most critical or sensitive assets from the less critical or sensitive ones, and apply different levels of security controls to each zone according to the risk assessment. Security zones are not necessarily aligned with physical network segments, as assets within the same network may have different security requirements. For example, a network segment may contain both a safety instrumented system (SIS) and a human-machine interface (HMI), but the SIS has a higher security requirement than the HMI. Therefore, the SIS and the HMI should be in different security zones, even if they are in the same network segment. Similarly, assets within the same logical communication network may not have the same security requirements, and therefore should not be in the same security zone. For example, a logical communication network may span across multiple physical locations, such as a plant and a corporate office, but the assets in the plant may have higher security requirements than the assets in the office. Therefore, the assets in the plant and the office should be in different security zones, even if they are in the same logical communication network. Finally, all components in a large or complex system should not be in the same security zone, as this would create a single point of failure and expose the entire system to potential cyberattacks. Instead, the components should be divided into smaller and simpler security zones, based on their security requirements, and the communication between the zones should be controlled by conduits. Conduits are logical or physical connections between security zones that allow data flow and access control. Conduits should be designed to minimize the attack surface and the potential impact of cyberattacks, by applying security controls such as firewalls, encryption, authentication, and authorization. References:

• How to Define Zones and Conduits1
• Securing industrial networks: What is ISA/IEC 62443?2
• ISA/IEC 62443 Series of Standards3

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 .

References:

• 1: ISASecure - IEC 62443 Conformance Certification - Official Site
• 2: ISASecure - IEC 62443 Conformance Certification - Official Site
• [3]: ISA/IEC 62443-4-1: Secure Product Development Lifecycle Requirements, ISA, 2018.
• [4]: ISA/IEC 62443-4-2: Technical Security Requirements for IACS Components, ISA, 2019.
• [5]: ISA/IEC 62443-4-2: Technical Security Requirements for IACS Components, ISA, 2019.
• [6]: ISA/IEC 62443-3-3: System Security Requirements and Security Levels, ISA, 2013.

The NIST CSF is a voluntary framework that provides a set of standards, guidelines, and best practices to help organizations manage cybersecurity risks. The NIST CSF consists of five core functions: Identify, Protect, Detect, Respond, and Recover. Each function is further divided into categories and subcategories that describe specific outcomes and activities. The NIST CSF also provides informative references that link the subcategories to existing standards, guidelines, and practices that can help organizations achieve the desired outcomes. The informative references are not mandatory or exhaustive, but rather serve as examples of possible sources of guidance. The ISA 62443 standards are used as informative references in the NIST CSF v1.0 for several subcategories, especially in the Protect and Detect functions. The ISA 62443 standards are a series of standards that provide a framework for securing industrial automation and control systems (IACS). The ISA 62443 standards cover various aspects of IACS security, such as terminology, concepts, requirements, policies, procedures, and technical specifications. The ISA 62443 standards are aligned with the NIST CSF in terms of the core functions and the risk-based approach. Therefore, the ISA 62443 standards can provide useful guidance and best practices for organizations that use IACS and want to implement the NIST CSF. References:

• NIST Cybersecurity Framework - Official Site1
• Framework for Improving Critical Infrastructure Cybersecurity - Version 1.02
• ISA/IEC 62443 Standards - Official Site3
• ISA/IEC 62443 Compliance & Scoring | Centraleyes4

According to the ISA/IEC 62443-1-1 standard, an industrial automation and control system (IACS) is defined as a collection of personnel, hardware, and software that can affect or influence the safe, secure, and reliable operation of an industrial process. The hardware and software components of an IACS include the control system, which is the combination of control devices, networks, and applications that perform the control functions for the industrial process. The control system may consist of various types of devices, such as distributed control systems (DCS), programmable logic controllers (PLC), supervisory control and data acquisition (SCADA) systems, human-machine interfaces (HMI), remote terminal units (RTU), intelligent electronic devices (IED), sensors, actuators, and other field devices. The control system may also use commercial off-the-shelf (COTS) software and hardware, such as operating systems, databases, firewalls, routers, switches, and servers, to support the control functions and communication.

References:

• ISA/IEC 62443-1-1:2009, Security for industrial automation and control systems - Part 1-1: Terminology, concepts and models, Clause 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 3.2.12

 Layer 1 of the ISO/OSI protocol stack is the physical layer, which provides the means of transmitting and receiving raw data bits over a physical medium. It defines the electrical and physical specifications of the data connection, such as the voltage levels, signal timing, cable types, connectors, and pin assignments. It does not perform any data encryption, routing, end-to-end connectivity, framing, error checking, or user applications. These functions are performed by higher layers of the protocol stack, such as the data link layer, the network layer, the transport layer, and the application layer. References: ISO/IEC 7498-1:1994, Section 6.11; ISA/IEC 62443 Cybersecurity Fundamentals Specialist Study Guide, Section 3.1.12

Phishing is a type of cyberattack that relies on a human weakness to succeed. Phishing is the practice of sending fraudulent emails or other messages that appear to come from a legitimate source, such as a bank, a government agency, or a trusted person, in order to trick the recipient into revealing sensitive information, such as passwords, credit card numbers, or personal details, or into clicking on malicious links or attachments that may install malware or ransomware on their devices. Phishing is a common and effective way of compromising the security of industrial automation and control systems (IACS), as it can bypass technical security measures by exploiting the human factor. Phishing can also be used to gain access to the IACS network, to conduct reconnaissance, to launch further attacks, or to cause damage or disruption to the IACS operations. The ISA/IEC 62443 series of standards recognize phishing as a potential threat vector for IACS and provide guidance and best practices on how to prevent, detect, and respond to phishing attacks. Some of the recommended countermeasures include:

• Educating and training the IACS staff on how to recognize and avoid phishing emails and messages, and how to report any suspicious or malicious activity.
• Implementing and enforcing policies and procedures for email and message security, such as using strong passwords, verifying the sender’s identity, and not opening or clicking on unknown or unsolicited links or attachments.
• Applying technical security controls, such as antivirus software, firewalls, spam filters, encryption, and authentication, to protect the IACS devices and network from phishing attacks.
• Monitoring and auditing the IACS network and devices for any signs of phishing attacks, such as anomalous or unauthorized traffic, connections, or activities, and taking appropriate actions to contain and mitigate the impact of any incidents. References:
• ISA/IEC 62443-1-1:2009, Security for industrial automation and control systems - Part 1-1: Terminology, concepts and models1
• 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 62443-2-4:2015, Security for industrial automation and control systems - Part 2-4: Security program requirements for IACS service providers3
• ISA/IEC 62443-3-3:2013, Security for industrial automation and control systems - Part 3-3: System security requirements and security levels4
• ISA/IEC 62443-4-2:2019, Security for industrial automation and control systems - Part 4-2: Technical security requirements for IACS components5

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

According to the OSI model, the physical address is assigned in the layer 2, also known as the data link layer. The physical address is a unique identifier for each device on a network, such as a MAC address or a serial number. The data link layer is responsible for transferring data between adjacent nodes on a network, using the physical address to identify the source and destination of each frame. The data link layer also provides error detection and correction, flow control, and media access control. References: ISA/IEC 62443 Cybersecurity Fundamentals Specialist Exam Prep, section 2.2; ISA/IEC 62443 Standards to Secure Your Industrial Control System, section 3.1.2.

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.

Datagram Transport Layer Security (DTLS) and Secure Sockets Layer (SSL) are both commonly used protocols for managing secure data transmission on the Internet. DTLS is a variant of SSL that is designed to work over datagram protocols such as UDP, which are used for real-time applications such as voice and video. SSL is a protocol that provides encryption, authentication, and integrity for data transmitted over TCP, which is used for reliable and ordered delivery of data. Both DTLS and SSL use certificates and asymmetric cryptography to establish a secure session between the communicating parties, and then use symmetric cryptography to encrypt the data exchanged. DTLS and SSL are widely used in web browsers, email clients, VPNs, and other applications that require secure communication over the Internet. References:

• ISA/IEC 62443 Standards to Secure Your Industrial Control System, Module 3: Introduction to Cryptography, pages 3-5 to 3-7
• Using the ISA/IEC 62443 Standards to Secure Your Control System, Chapter 6: Securing Communications, pages 125-126

 Intrusion detection systems (IDS) are tools that monitor network traffic and detect suspicious or malicious activity based on predefined rules or signatures. They are effective against known vulnerabilities, as they can alert the system administrators or security personnel when they encounter a match with a known attack pattern or behavior. However, IDS have some limitations and challenges, especially when applied to industrial automation and control systems (IACS). Some of these are:

• Modern IDS do not recognize IACS devices by default, as they are designed for general-purpose IT networks and protocols. Therefore, they may generate false positives or negatives when dealing with IACS-specific devices, protocols, or traffic patterns. To overcome this, IDS need to be customized or adapted to the IACS environment and context, which may require additional expertise and resources.
• They are not very inexpensive to design and deploy, as they require careful planning, configuration, testing, and maintenance. They also need to be integrated with other security tools and processes, such as firewalls, antivirus, patch management, incident response, etc. Moreover, they may introduce additional costs and risks, such as network performance degradation, data privacy issues, or legal liabilities.
• They are not effective against unknown or zero-day vulnerabilities, as they rely on predefined rules or signatures that may not cover all possible attack scenarios or techniques. Therefore, they may fail to detect novel or sophisticated attacks that exploit new or undiscovered vulnerabilities. To mitigate this, IDS need to be complemented with other security measures, such as anomaly detection, threat intelligence, or machine learning.
• They require a significant amount of care and feeding, as they need to be constantly updated, tuned, and monitored. They also generate a large amount of data and alerts, which may overwhelm the system administrators or security personnel. Therefore, they need to be supported by adequate tools and processes, such as data analysis, alert filtering, prioritization, correlation, or visualization.

References: ISA/IEC 62443-2-1:2010 - Establishing an industrial automation and control system security program, ISA/IEC 62443-3-3:2013 - System security requirements and security levels, ISA/IEC 62443 Cybersecurity Fundamentals Specialist Training Course, [Enhancing Modbus/TCP-Based Industrial Automation and Control Systems Security Using Intrusion Detection Systems]

 IPSec is a commonly used protocol for managing secure data transmission over a VPN. IPSec stands for Internet Protocol Security and it is a set of standards that define how to encrypt and authenticate data packets that travel between two or more devices over an IP network. IPSec can operate in two modes: transport mode and tunnel mode. In transport mode, IPSec only encrypts the payload of the IP packet, leaving the header intact. In tunnel mode, IPSec encrypts the entire IP packet and encapsulates it in a new IP header. Tunnel mode is more secure and more suitable for VPNs, as it can protect the original source and destination addresses of the IP packet from eavesdropping or spoofing. IPSec uses two main protocols to provide security services: Authentication Header (AH) and Encapsulating Security Payload (ESP). AH provides data integrity and source authentication, but not confidentiality. ESP provides data integrity, source authentication, and confidentiality. IPSec also uses two protocols to establish and manage security associations (SAs), which are the parameters and keys used for encryption and authentication: Internet Key Exchange (IKE) and Internet Security Association and Key Management Protocol (ISAKMP). IKE is a protocol that negotiates and exchanges cryptographic keys between two devices. ISAKMP is a protocol that defines the format and structure of the messages used for key exchange and SA management.

References:

• ISA/IEC 62443-3-3:2018, Section 4.2.3.7.1, VPN1
• ISA/IEC 62443-4-2:2019, Section 4.2.3.7.1, VPN
• ISA/IEC 62443 Cybersecurity Fundamentals Specialist Study Guide, Section 5.3.2, VPN
• ISA/IEC 62443 Cybersecurity Fundamentals Specialist Exam Specification, Section 5.3.2, VPN

 According to the ISA/IEC 62443 Cybersecurity Fundamentals Specialist resources, patches are software updates that fix bugs, vulnerabilities, or improve performance of a system. Patches are classified into three categories based on their urgency and impact: low, medium, and high. Low priority patches are those that have minimal or no impact on the system functionality or security, and can be applied at the next scheduled maintenance. Medium priority patches are those that have moderate impact on the system functionality or security, and should be applied within a reasonable time frame, such as three months. High priority patches are those that have significant or critical impact on the system functionality or security, and should be applied as soon as possible, preferably at the first unscheduled outage. Applying patches in a timely manner is a best practice for maintaining the security and reliability of an industrial automation and control system (IACS). References:

• ISA/IEC 62443 Cybersecurity Fundamentals Specialist Study Guide, Section 4.3.2, Patch Management
• ISA/IEC 62443-2-1:2009, Security for industrial automation and control systems - Part 2-1: Establishing an industrial automation and control systems security program, Clause 5.3.2.2, Patch management
• ISA/IEC 62443-3-3:2013, Security for industrial automation and control systems - Part 3-3: System security requirements and security levels, Clause 4.3.3.6.2, Patch management

One of the trends that has increased the security risks for industrial automation and control systems (IACS) is the integration of these systems with business and enterprise systems, such asenterprise resource planning (ERP), manufacturing execution systems (MES), and supervisory control and data acquisition (SCADA). This integration exposes the IACS to the same threats and vulnerabilities that affect the business and enterprise systems, such as malware, denial-of-service attacks, unauthorized access, and data theft. Moreover, the integration also creates new attack vectors and pathways for adversaries to compromise the IACS, such as through remote access, wireless networks, or third-party devices. Therefore, the integration of IACS with business and enterprise systems is a trend that has caused a significant percentage of security vulnerabilities. References: ISA/IEC 62443 Standards to Secure Your Industrial Control System, page 1-2.

 A router and a VPN can be employed as barrier devices in a segmented network. A barrier device is a device that controls the flow of traffic between different network segments, based on predefined rules and policies1. A router is a device that forwards packets between different networks, based on their IP addresses2. A router can act as a barrier device by applying access control lists (ACLs) or firewall rules to filter or block unwanted or malicious traffic2. A VPN is a technology that creates a secure and encrypted tunnel between different networks, such as a remote site and a corporate network3. A VPN can act as a barrier device by encrypting the traffic and authenticating the users or devices that access the network3. A VPN can also prevent unauthorized access or eavesdropping by outsiders3.

References: LAYERING NETWORK SECURITY - CISA, Router (computing) - Wikipedia, What Is Network Segmentation? - Cisco.

 Safety management staff are stakeholders of the CSMS, which stands for Cybersecurity Management System. The CSMS is a framework for managing the cybersecurity of industrial automation and control systems (IACS) based on the ISA/IEC 62443-2-1 standard1. The CSMS defines the objectives, policies, metrics, and governance for the overall ICS security program2. The CSMS also includes the processes for risk assessment, security design, implementation, monitoring, and improvement3. Safety management staff are involved in the CSMS development and implementation, as they are responsible for ensuring the safety of the IACS and the people, environment, and assets that depend on it. Safety management staff need to coordinate with the security management staff to align the safety and security requirements, identify and mitigate the safety risks arising from cyber threats, and monitor and respond to safety incidents caused by cyberattacks. References:

• 1: ISA/IEC 62443-2-1: Establishing an Industrial Automation and Control Systems Security Program, ISA, 2010.
• 2: A Practical Approach to Adopting the IEC 62443 Standards - ISAGCA
• 3: ISA ISA-IEC-62443 ISA/IEC 62443 Cybersecurity Fundamentals Specialist Online Training - Exam4Training
• [4]: Using the ISA/IEC 62443 Standards to Secure Your Control System, ISA, 2018.

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

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

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.

In cybersecurity, a demilitarized zone (DMZ) refers to a physical or logical subnetwork that contains and exposes an organization's external-facing services to an untrusted network, typically the internet. The main characteristic of a DMZ is that it acts as a buffer zone between the public internet and the private network. This allows for internet access through the firewall while keeping the internal network secure. Internet-facing servers are placed in the DMZ so that they are separated from the rest of the internal network. By doing so, if a server in the DMZ is compromised, the attacker would not have direct access to the internal network. This architecture is commonly used to host services such as web servers, mail servers, and FTP servers. Choice C is the most closely associated with the deployment of a DMZ as it allows for regulated and monitored internet access through a firewall.

OPC stands for Open Platform Communications, and it is a series of standards and specifications for industrial telecommunication based on Object Linking and Embedding (OLE) for process control. It allows the communication of real-time data between devices from different manufacturers using various data transportation technologies, such as Microsoft’s OLE, COM, DCOM, .NET, XML, and TCP123. OPC is not a protocolitself, but rather a standardized approach for data connectivity supported by the OPC Foundation3. OPC is widely used in industrial automation and control systems, as well as other industries, to achieve interoperability and integration between different applications and devices3.

A is incorrect, because OPC is not a field bus protocol, but rather a standard for data exchange between devices that may use different field bus protocols, such as Modbus, Profibus, or Ethernet/IP2. C is incorrect, because OPC is not a serial communications protocol, but rather a standard that can use various data transportation technologies, including serial, Ethernet, or wireless2. D is incorrect, because OPC is not a vendor-specific proprietary protocol, but rather an open standard that can be implemented by any vendor or device that supports the OPC specifications3. References: 1: Open Platform Communications - Wikipedia 2: What is OPC Protocol - The Automization 3: What is OPC? - OPC Foundation

 Network security is important in IACS environments because PLCs, or programmable logic controllers, are devices that control physical processes and equipment in industrial settings. PLCs under cyber attack can have costly and dangerous impacts, such as disrupting production, damaging equipment, compromising safety, and harming the environment. Therefore, network security is essential to protect PLCs and other IACS components from unauthorized access, modification, or disruption. The other choices are not primary reasons why network security is important in IACS environments. PLCs are not inherently unreliable, but they can be affected by environmental factors, such as temperature, humidity, and electromagnetic interference. PLCs are programmed using ladder logic, which is a graphical programming language that resembles electrical schematics. PLCs use serial or Ethernet communications methods, depending on the type and age of the device, to communicate with other IACS components, such as human-machine interfaces (HMIs), supervisory control and data acquisition (SCADA) systems, and distributed control systems (DCSs). References:

• ISA/IEC 62443 Standards to Secure Your Industrial Control System training course1
• ISA/IEC 62443 Cybersecurity Fundamentals Specialist Study Guide2
• Using the ISA/IEC 62443 Standard to Secure Your Control Systems3