ISA ISA-IEC-62443 - ISA/IEC 62443 Cybersecurity Fundamentals Specialist

ISA/IEC 62443 recommends protocol-aware security controls for IACS networks to protect real-time communications.

Step 1: ICS protocol awareness

IACS-specific firewalls understand industrial protocols such as Modbus, DNP3, and IEC 61850, allowing precise control without breaking deterministic behavior.

Step 2: Deep packet inspection (DPI)

DPI enables inspection of commands and function codes, blocking unauthorized actions while allowing legitimate traffic.

Step 3: Why other options are unsuitable

General-purpose firewalls lack protocol awareness. Data diodes restrict bidirectional control. Basic packet filters cannot inspect commands.

Therefore, the correct choice is IACS-specific firewall with deep packet inspection.

One of the reasons for the increase in attacks on IACS is the availability of information and tools that can be used to exploit vulnerabilities in these systems. The Internet provides a platform for hackers, researchers, and activists to share their knowledge and techniques for compromising IACS. Some examples of such information and tools are:

Stuxnet: A sophisticated malware that targeted the Iranian nuclear program in 2010. It exploited four zero-day vulnerabilities in Windows and Siemens software to infect and manipulate the programmable logic controllers (PLCs) that controlled the centrifuges. Stuxnet was widely analyzed and reported by the media and security experts, and its source code was leaked online1.

Metasploit: A popular penetration testing framework that contains modules for exploiting various IACS components and protocols. For instance, Metasploit includes modules for attacking Modbus, DNP3, OPC, and Siemens S7 devices2.

Shodan: A search engine that allows users to find devices connected to the Internet, such as webcams, routers, printers, and IACS components. Shodan can reveal the location, model, firmware, and configuration of these devices, which can be used by attackers to identify potential targets and vulnerabilities3.

ICS-CERT: A website that provides alerts, advisories, and reports on IACS security issues and incidents. ICS-CERT also publishes vulnerability notes and mitigation recommendations for various IACS products and vendors4. These sources of information and tools can be useful for legitimate purposes, such as security testing, research, and education, but they can also be misused by malicious actors who want to disrupt, damage, or steal from IACS. Therefore, IACS owners and operators should be aware of the threats and risks posed by the Internet and implement appropriate security measures to protect their systems. References:

The increase in attacks on Industrial Automation and Control Systems (IACS) can be attributed to several factors, including: A. Use of proprietary communications protocols: These can pose security risks because they may not have been designed with security in mind and are often not as well-tested against security threats as more standard protocols. C. Knowledge of exploits and tools readily available on the Internet: The availability of information about vulnerabilities and exploits on the internet has made it easier for attackers to target IACS.

The other options, B and D, are incorrect because: B. The move towards commercial off-the-shelf (COTS) systems, protocols, and networks actually increases risk because these systems are more likely to be known and targeted by attackers, compared to proprietary systems which might benefit from security through obscurity. D. There is actually an increase in risk with more personnel with system knowledge because it enlarges the attack surface – each individual with system knowledge can potentially become a vector for an attack, either maliciously or accidentally.

The second edition (2024) of ISA/IEC 62443-2-1 introduced a significant structural improvement by eliminating duplication of Information Security Management System (ISMS) requirements. The first edition (2010) contained content that overlapped substantially with ISO/IEC 27001-style ISMS controls, leading to redundancy and unnecessary implementation burden.

In the updated edition, ISA clarified that 62443-2-1 is not intended to replace a general-purpose ISMS, but rather to extend and specialize it for Industrial Automation and Control Systems (IACS). As a result, duplicated ISMS clauses were removed or streamlined, and the focus shifted to IACS-specific risks, operational realities, and lifecycle concerns.

This change improves:

Compatibility with existing enterprise ISMS implementations

Clarity of roles between IT security governance and OT security management

Practical adoption by asset owners operating both IT and OT environments

Importantly, supply chain security, lifecycle management, and organizational governance were not removed. Instead, they were better aligned and referenced to avoid redundancy. The PDCA model remains implicit but was not newly introduced in 2024.

Thus, the defining change is the elimination of duplicated ISMS requirements, making Option B correct.

In ISA/IEC 62443, a conduit is a logical or physical communication path used to connect security zones and is typically composed of:

Routers and switches

Network cabling (wiring)

Firewalls and network management devices

“A conduit is used to implement the flow of data between zones, and includes the communication hardware and associated logical controls such as firewalls, switches, and routers.”

— ISA/IEC 62443-1-1:2007, Clause 3.3.44 – Conduit

This differs from physical electrical conduits, which are not a cybersecurity concept.

ISA/IEC 62443-2-1 explicitly requires that the IACS Security Program be integrated into the organization’s overall management structure.

Step 1: Integration principle

The standard states that IACS security must align with business processes, governance, and enterprise security management rather than operate in isolation.

Step 2: Alignment with ISMS

Where an Information Security Management System (ISMS) exists, the IACS SP should be embedded within it to ensure consistent risk management, policy enforcement, and continuous improvement.

Step 3: Why other options are incorrect

Standalone security programs create silos. Full outsourcing violates asset owner accountability. Purely technical approaches ignore human and process factors.

Step 4: Operational outcome

Embedding the SP ensures sustainability, consistency, and executive oversight.

Therefore, the correct answer is by embedding it into organizational processes and the ISMS.

One of the most frequent mistakes in cybersecurity management—according to ISA/IEC 62443 guidance—is focusing only on technological solutions and neglecting other critical components such as people, process, and culture. Effective cybersecurity management must include policies, training, incident response, and continual improvement, not just technical controls. This holistic approach is emphasized throughout the standards, particularly in the sections describing CSMS program elements and organizational responsibilities.

The ISA/IEC 62443 series organizes documents into categories: General, Policies and Procedures, System, and Component. The document titled "Patch management in the IACS environment" is part of the Policies and Procedures group (specifically, ISA/IEC 62443-2-3). This group addresses processes, procedures, and organizational measures for cybersecurity in industrial automation and control systems (IACS), including topics like patch management, which deals with evaluating, testing, and installing updates or patches to reduce vulnerabilities in control systems.

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.