Free Practice Questions for ISA ISA-IEC-62443 Exam

The “Addressing Risk” CSMS category consists of three element groups: Security Policy, Organization and Awareness; Selected Security Countermeasures; and Implementation of Security Program1. These element groups cover the aspects of defining the security objectives, roles and responsibilities, policies and procedures, awareness and training, security countermeasures selection and implementation, and security program execution and maintenance1. The “Addressing Risk” CSMS category aims to reduce the security risk to an acceptable level by applying appropriate security measures to the system under consideration (SuC)1. References: 1: ISA/IEC 62443-2-1: Security for industrial automation and control systems: Establishing an industrial automation and control systems security program

 The ISA/IEC 62443 series of standards is organized into four main categories for documents, based on the topics and perspectives that they cover. These categories are: General, Policies and Procedures, System, and Component12.

General: This category covers topics that are common to the entire series, such as terms, concepts, models, and overview of the standards1. For example, ISA/IEC 62443-1-1 defines the terminology, concepts, and models for industrial automation and control systems (IACS) security3.

Policies and Procedures: This category focuses on methods and processes associated with IACS security, such as risk assessment, system design, security management, and security program development1. For example, ISA/IEC 62443-2-1 specifies the elements of an IACS security management system, which defines the policies, procedures, and practices to manage the security of IACS4.

System: This category is about requirements at the system level, such as security levels, security zones, security lifecycle, and technical security requirements1. For example, ISA/IEC 62443-3-3 specifies the system security requirements and security levels for zones and conduits in an IACS5.

Component: This category provides detailed requirements for IACS products, such as embedded devices, network devices, software applications, and host devices1. For example, ISA/IEC 62443-4-2 specifies the technical security requirements for IACS components, such as identification and authentication, access control, data integrity, and auditability.

The other options are not valid categories for documents in the ISA/IEC 62443 series of standards, as they either do not reflect the structure and scope of the standards, or they mix different aspects of IACS security that are covered by different categories. For example, end-user, integrator, vendor, and regulator are not categories for documents, but rather roles or stakeholders that are involved in IACS security. Assessment, mitigation, documentation, and maintenance are not categories for documents, but rather activities or phases that are part of the IACS security lifecycle. People, processes, technology, and training are not categories for documents, but rather elements or dimensions that are essential for IACS security.

References:

ISA/IEC 62443 Series of Standards - ISA1

IEC 62443 - Wikipedia2

ISA/IEC 62443-1-1: Concepts and models3

ISA/IEC 62443-2-1: Security management system4

ISA/IEC 62443-3-3: System security requirements and security levels5

ISA/IEC 62443-4-2: Technical security requirements for IACS components

 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

 Layer 2 of the OSI model is the data link layer, which is responsible for transferring data frames between nodes on a network segment. The data link layer is divided into two sublayers: logical link control (LLC) and media access control (MAC). The LLC sublayer deals with issues common to both dedicated and broadcast links, such as framing, flow control, and error control. The MAC sublayer deals with issues specific to broadcast links, such as how to access the shared medium and avoid collisions. The LLC and MAC sublayers are not related to the ISA/IEC 62443 cybersecurity standards, which focus on the security of industrial automation and control systems (IACS). References:https://www.baeldung.com/cs/data-link-sub-layers

https://bing.com/search?q=Layer+2+sublayers

 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]

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.

 OPC Classic uses DCOM, which dynamically assigns any port between 1024 and 65535. Comprehensive Explanation: OPC Classic is a software interface technology that uses the Distributed Component Object Model (DCOM) protocol to facilitate the transfer of data between different industrial control systems. DCOM is a Microsoft technology that allows applications to communicate across a network. However, DCOM is not designed with security in mind, and it poses several challenges for firewall configuration. One of the main challenges is that DCOM does not use fixed TCP port numbers, but rather negotiates new port numbers within the first open connection. This means that intermediary firewalls can only be used with wide-open rules, leaving a large range of ports open for potential attacks. This makes OPC Classic very “firewall unfriendly” and reduces the security and protection they provide. References:

Tofino Security OPC Foundation White Paper

Step 2 (for client or server): Configuring firewall settings - GE

Secure firewall for OPC Classic - Design World

According to the ISA/IEC 62443-2-1 standard, security policy, organization, and awareness is one of the four foundational requirements for an IACS security management system. It defines the “policies, procedures, and organizational structure necessary to support the security program” 1. One of the elements of this requirement is staff training and security awareness, which involves “providing appropriate security education and training to all personnel who have access to or are responsible for IACS components” 1. This element aims to ensure that the staff are aware of the security risks, policies, and procedures, and are able to perform their roles and responsibilities in a secure manner. Staff training and security awareness can include topics such as security principles, threats and vulnerabilities, incident response, password management, physical security, and social engineering 2. References:

ISA/IEC 62443 Series of Standards - ISA

Security of Industrial Automation and Control Systems - ISAGCA

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.

 A recommended default rule for IACS firewalls is to block all traffic by default, and then allow only the necessary and authorized traffic based on the security policy and the zone and conduit model. This is also known as the principle of least privilege, which means granting the minimum access required for a legitimate purpose. Blocking all traffic by default provides a higher level of security and reduces the attack surface of the IACS network. The other choices are not recommended default rules for IACS firewalls, as they may expose the IACS network to unnecessary risks. Allowing all traffic by default would defeat the purpose of a firewall, as it would not filter any malicious or unwanted traffic. Allowing IACS devices to access the Internet would expose them to potential cyber threats, such as malware, phishing, or denial-of-service attacks. Allowing traffic directly from the IACS network to the enterprise network would bypass the demilitarized zone (DMZ), which is a buffer zone that isolates the IACS network from the enterprise network and hosts services that need to communicate between them. 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