ISA Updated ISA-IEC-62443 Exam Questions and Answers by mikey

The primary objective of the IACS Security Program, as defined in ISA/IEC 62443-2-1, is to establish a structured and sustainable approach for the mitigation of cybersecurity risks throughout the IACS lifecycle.

“The purpose of the IACS security program is to manage and mitigate risk associated with cybersecurity threats. It defines policies, procedures, and practices to reduce the likelihood and impact of security incidents.”

— ISA/IEC 62443-2-1:2010, Clause 4.1 – Security Program Overview

The standard clearly distinguishes between risk mitigation and risk elimination — the latter being infeasible in industrial environments.

ISA/IEC 62443-3-2 introduces the concept of the System under Consideration (SuC) as the scope boundary for risk assessment.

Step 1: Purpose of the SuC

The SuC defines exactly what is being analyzed for cybersecurity risk.

Step 2: Inclusive scope

It includes a defined collection of IACS components, systems, zones, conduits, and supporting assets that contribute to the system’s function.

Step 3: Why definition matters

A clearly defined SuC ensures accurate threat modeling, impact analysis, and Security Level determination.

Step 4: Why other options are incorrect

Limiting the SuC to business assets or physical devices ignores logical, networked, and functional dependencies.

Therefore, the correct answer is a defined collection of IACS and related assets.

 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

System availability is a core objective of ISA/IEC 62443, reflected in the Resource Availability (RA) foundational requirement. When frequent shutdowns occur, the standard directs attention to recovery and resilience mechanisms.

Step 1: Role of SP Element 8

SP Element 8 addresses backup, restore, and recovery capabilities. These activities ensure that systems can be restored quickly and reliably following failures, cyber incidents, or operational errors.

Step 2: Availability focus

Unexpected shutdowns often reveal weaknesses in backup integrity, restoration procedures, or recovery testing. ISA/IEC 62443 requires backups to be verified, protected, and periodically tested to ensure operational continuity.

Step 3: Why other SP Elements are secondary

Supply chain security, change control, and logging are important but do not directly restore operations after shutdowns. Backup and recovery directly impact downtime reduction.

Step 4: Operational outcome

Reviewing SP Element 8 activities helps identify gaps in restoration time objectives, backup completeness, and recovery procedures.

Thus, SP Element 8 – Backup restoration is the most relevant.