Module 1-10 Flashcards
(47 cards)
Assess Phase?
- High-Level Cyber Risk Assessment
- Allocation of IACS assets to Zones/Conduits
- Detailed Risk Assessment
62443-3-2
Development & Implementation Phase?
- CRS
62443-3-2 - Design and Engineering of Cybersecurity Countermeasures (CC)
62443-3-3 - Installation, Commissioning, and Validation of CC
Maintain Phase?
- Cybersecurity Maintenance, Monitoring, and MoC
- Cyber Incident Response and Recovery
62443-2-1
Continuous Process
Cybersecurity Management System (CMS): Policies, Procedures, Training, and Awareness
Periodic Cybersecurity Audits
62443-2-1
Interpreting CRS
The output of the risk assessment (CRS) is the input for the Development & Implementation
Security Level (SL) Definitions
0 = No reqs. or security protection needed.
1 = Protection against casual/coincidental violation
2 = Protection against intentional violation with low resources/skill/motivation
3 = Protection against intentional violation with moderate resource/IACS skill/motivation
4 = Protection against intentional violation with extended resource/IACS skill/motivation
SL Types
SL-T = desired security level for system
SL-A = actual security level of system
SL-C = potential security level of system
Four Ts for Managing Risk
Terminate
Tolerate
Transfer
Treat
5 Ds of Treating Risk
Defeat
Delay
Deny
Detect
Deter
Steps to Developing a Security Strategy
I R E I D
Identify Zones
Review Risk Assessment results
Establish SL-T
Identify Physical and Cyber Access points
Develop 5D physical & cyber strategy for each point
Seven Foundational Requirements (62443-3-3)
I U S D R T R
1. Identity and Authentication Control
2. Use Control
3. System Integrity
4. Data Confidentiality
5. Restricted Data Flow
6. Timely Response to Events
7. Resource Availability
FR Technologies
System Integrity: Malware/Anti-virus
Data Confidentiality: Encryption
Both: Physical security, secure protocols
Restricted Data Flow: Firewall, VLAN
Timely Response to Events: IDS/IPS
Resource Availability: Backup/recovery tools
62443-4-2 Overview
Used by suppliers to identify security capabilities of their components (Software App, Embedded Device, Host Device, Network Device)
Series of Component Requirement (CR) and Requirement Enhancements (RE)
Expands System Requirements (SR) and RE
Network types for IACS
Mesh, Star/Hub, Spoke, Ring, Bus, Hybrid
ISO/OSI Reference model layers and description
- Physical - physics of getting messages between devices (Ethernet - IEEE 802.3)
- Data Link - rules for framing, converting electrical signals to data, physical/MAC addressing (802.3)
- Network - routing messages through complex network (IP, ICMP, ARP)
- Transport - transparent transfer of data between systems/hosts, end2end recovery, flow control (TCP/UDP)
- Session - persistent logical linking of 2 software apps, mechanism for opening, closing, managing sessions (RPC)
- Presentation - delivers/formats data for L7 data, format conversion, encryption/security, SSL
- Application - interfaces with software apps that have a communicating component, Email (SMTP), File (FTP),
HTTP
Problems with OSI model?
Layer specification is FUNCTIONAL only
Too complex for many applications such as industrial protocols where L5,6,7 are combined
How do Network Discovery and Security Auditing Tools affect IACS
May adversely affect hazardous materials/operations/equipment
Safety systems could be triggered
Disrupt the flow of the control system
Three classes of firewalls
Packet Filter - filters based on packet headers
Stateful Inspection - tracks state of connections and blocks packets that deviate from state
3 states Connection Establishment, Usage, Termination
Deep Packet Inspection - basic intrusion detection technology that analyses protocols for malware
Steps in Firewall Planning
P I T D M
Plan - select technologies
Install & Configure - Install device, soft/firmware, patch/update. Configure users, policies, rules, ACLs
Test - Connectivity, rulesets, security, performance
Deploy - notify users, integration with routers/switches, test, back up
Manage - Maintain policies, patching, MoC, Config mgmt., Logs, Audits
IACS Firewall configuration best practices
Deny all, allow by exception
No direct connections from internet to ICS network
Restrict access between CORP/PROD
Host Intrusion Detection System (HIDS)
Monitors and analyzes internal and network interfaces on a single host
Agents monitor SI, applications activity, file changes, logs, Policy enforcement
NIDS vs HIDS
Broad vs Narrow
Near real-time vs after suspicious activity
Bandwidth-dependent vs independent
High false positive rates vs low
Hardware vs no hardware
IDS Best practices
Distributed Deployment
Use SCADA IDS Signatures
Careful not to block necessary traffic with IPS
Security Requirements (SRs)
CAD SIR
Confidentiality
Access control,
Data flow,
Security event monitoring,
Industry/regulatory standards
Risk assessment