ISA/IEC 62443 Lead Implementer flashcards
ISA/IEC 62443 Lead Implementer · Build recall with a focused review session.
33 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Purdue Level 0
- The physical process level containing sensors and actuators that interact directly with the industrial process. Security controls here are usually physical or embedded in the device itself.
- Purdue Level 3.5 DMZ
- A demilitarised zone separating site operations from enterprise networks. It terminates conduits and brokers data exchange so no direct path exists between Level 3 and Level 4.
- Zone definition
- A grouping of logical or physical assets sharing common security requirements, defined by risk assessment rather than by network topology alone. Each zone receives a target security level.
- Conduit definition
- A controlled communication path between two zones that enforces the security requirements of both. It specifies permitted protocols, direction, and inspection controls.
- Security Level 1
- Protection against casual or unintentional violation using simple means, low motivation, and few resources. Suitable for low-consequence zones with limited exposure.
- Security Level 2
- Protection against intentional violation using simple means with low resources and generic skills. Attackers are opportunistic and use commonly available tools.
- Security Level 3
- Protection against intentional violation using sophisticated means with moderate resources and IACS-specific knowledge. Requires defence against targeted attacks by competent adversaries.
- Security Level 4
- Protection against intentional violation using sophisticated means with extended resources and high motivation, such as nation-state actors. Highest level defined in the 62443 series.
- Foundational Requirement FR1
- Identification and authentication control. Requires verifying identity of users and devices before granting access to the IACS, including unique accounts and strong authentication.
- Foundational Requirement FR3
- System integrity. Requires protecting the integrity of the control system, detecting unauthorised modification, and verifying software and firmware authenticity.
- Foundational Requirement FR5
- Restricted data flow. Requires segmenting the system into zones and conduits and enforcing that only authorised traffic crosses zone boundaries.
- Foundational Requirement FR7
- Resource availability. Requires ensuring the control system remains available under adverse conditions, including denial-of-service resistance and redundancy where needed.
- IACS priority ordering
- Safety first, then availability, integrity, and confidentiality last. This inverts the IT ordering and explains why patching and reboots are deferred in OT.
- Defence in depth
- Layering independent security controls so failure of any single measure does not expose the process. Layers span physical, network, host, application, and procedural controls.
- Safety instrumented system
- A system that brings the process to a safe state independently of the basic control system. It must not be disrupted by security controls or intrusive scanning.
- 62443 series structure
- 1-x covers general concepts and metrics, 2-x asset owner, 3-x system integrator, 4-x component supplier. Each part addresses a distinct role in the security lifecycle.
- Target security level
- The SL a zone or conduit must achieve, derived from risk assessment per 62443-3-2. It is compared against achieved SL to identify gaps.
- Achieved security level
- The SL actually demonstrated by a zone or system against the requirements. It is determined by verification evidence, not by vendor claims of component capability.
- SL gap analysis
- A comparison of required SR and RE against implemented controls. Unmet requirements are closed by remediation or a formally risk-accepted compensating control.
- Compensating control
- An alternative measure applied when a required requirement cannot be met directly. It must provide equivalent risk reduction and be documented and risk-accepted.
- Security lifecycle phases
- Assess, design, implement, operate, maintain, and decommission. Verification evidence is required at each transition, and the cycle repeats as the system changes.
- OT patch management
- Test patches in a representative lab, schedule within maintenance windows, keep rollback images, and apply virtual patching when vendor patches are unavailable or untested.
- Virtual patching
- Applying an intrusion prevention rule or network control to block exploitation of a known vulnerability when the device cannot be patched. It is a temporary compensating control.
- Passive network monitoring
- Observing control network traffic via span ports or taps without injecting packets. Used because active scanning can disrupt fragile Level 0–2 devices.
- Unidirectional gateway
- A device enforcing one-way data flow from a lower-trust zone to a higher-trust zone or vice versa. It physically prevents return traffic and is used for conduit enforcement.
- Conduit default deny
- A conduit rule set that blocks all traffic by default and permits only explicitly required protocols, sources, destinations, and directions. All crossings are logged.
- Least privilege in IACS
- Granting each account only the access needed for its role, with unique accounts and no shared credentials. Vendor default accounts must be removed before commissioning.
- Manual fallback procedure
- A documented, tested method for operating the process without the control system. It supports business continuity when recovery of automation is delayed.
- Configuration backup
- A stored copy of control system configuration and firmware used for recovery. It must be tested for restorability, not merely created and archived.
- Risk assessment 62443-3-2
- The process that identifies threats and vulnerabilities, evaluates consequence severity, and assigns target security levels to each zone and conduit.
- Component capability CL
- The security level a component can provide as specified by 62443-4-2. It is a supplier claim that must be verified against zone target requirements.
- Security requirements SR
- Specific requirements derived from the seven foundational requirements. Each SR maps to a foundational requirement and is associated with one or more security levels.
- Requirement enhancement RE
- An additional or stricter requirement that raises an SR to a higher security level. Presence of the relevant REs distinguishes SL1 from SL2, SL3, and SL4.