View
2.456
Download
0
Category
Preview:
Citation preview
Cyber Security SolutionsFor <Client Name>
Cyber Securityfor the Power Grid:
Cyber Security Issues & Securing Control Systems
Andrew Wright CTO, N-Dimension
andrew.wright@n-dimension.com
ACM CCS Conference TutorialNov. 2009
Power Grid Communications & Control Systems
borr
owed
from
NIS
T S
mar
t Grid
Tw
iki
Internet Control Systems
Agenda
• High-Level– Industrial Control Systems and Cyber Security Issues– Securing Control Systems
• Detailed– Security Issues in Industrial Control Systems– Today’s Threats– Securing Control Systems
A Control System
Sensor(s) +Actuator(s) +Controller(s)
Types of Industrial Control Systems (ICS)
Supervisory Control And Data Acquisition (SCADA)
Automation
Process Control Systems (PCS)
Distributed Control Systems (DCS)
Historical ICS
• Proprietary• Complete vertical solutions• Customized• Specialized communications
– Wired, fiber, microwave, dialup, serial, etc.– 100s of different protocols– Slow; e.g. 1200 baud
• Long service lifetimes: 15–20 years• Not designed with security in mind
Third PartyControllers,Servers, etc.
Serial, OPCor Fieldbus
EngineeringWorkplace
Device Network
Firewall
Services
Network
Third Party Application Server
ApplicationServer
HistorianServer
WorkplacesEnterprise
OptimizationSuite
MobileOperator
ConnectivityServer
Control
Network
Redundant
Enterprise Network
Serial RS485
Modern ICS Trends
IP
Internet
Enterprise Network
Technology Trends in ICS
• COTS (Commercial-Off-The-Shelf) technologies– Operating systems—Windows, WinCE, embedded RTOSes
– Applications—Databases, web servers, web browsers, etc.
– IT protocols—HTTP, SMTP, FTP, DCOM, XML, SNMP, etc.
– Networking equipment—switches, routers, firewalls, etc.
• Connectivity of ICS to enterprise LAN– Improved business visibility, business process efficiency
– Remote access to control center and field devices
• IP Networking– Common in higher level networks, gaining in lower levels
– Many legacy protocols wrapped in TCP or UDP
– Most new industrial devices have Ethernet ports
– Most new ICS architectures are IP-based
New IP-Based Industrial Control Systems
• ODVA (Rockwell)• Profinet• Foundation Fieldbus HSE• Telvent• ABB 800xA
• Honeywell Experion• Emerson DeltaV• Yokogawa VNET/IP• Invensys Infusion• Survalent
• IP to the Control Network or even Device Network• Not all are fully compatible with “ordinary IP”
Security Risks to Modern ICS
• COTS + IP + connectivity = many security risks• All of those of Enterprise networks and more
Worms and Viruses Legacy OSes and applications
DOS and DDOS impairing availability Inability to limit access
Unauthorized access Inability to revoke access
Unknown access Unexamined system logs
Unpatched systems Accidental misconfiguration
Little or no use of anti-virus Improperly secured devices
Limited use of host-based firewalls Improperly secured wireless
Improper use of ICS workstations Unencrypted links to remote sites
Unauthorized applications Passwords sent in clear text
Unnecessary applications Default passwords
Open FTP, Telnet, SNMP, HTML ports Password management problems
Fragile control devices Default OS security configurations
Network scans by IT staff Unpatched routers / switches
When ICS Security Fails
• Loss of production
• Penalties
• Lawsuits
• Loss of public trust
• Loss of market value
• Physical damage
• Environmental damage
• Injury
• Loss of life• USSR pipeline explosion, 1982
• Bellingham pipeline rupture, 1999
• Queensland sewage release, 2000
• Davis Besse nuclear plant infection, 2003
• Northeast USA blackout, 2003
• Browns Ferry nuclear plant scram, 2006$$$.$$
ACM CCS Tutorial
Nov. 2009
So How Do We Secure
Industrial Control Systems?
There is No Silver Bullet!
No Silver Bullet!
Defense in Depth
• Perimeter Protection– Firewall, IPS, VPN, AV– Host IDS, Host AV– DMZ
• Interior Security– Firewall, IDS, VPN, AV– Host IDS, Host AV– IEEE P1711 (AGA 12)
– NAC– Scanning
• Monitoring• Management
IDS Intrusion Detection SystemIPS Intrusion Prevention SystemDMZ DeMilitarized ZoneVPN Virtual Private Network (cryptographic)AV Anti-Virus (anti-malware)NAC Network Admission Control
Internet
Enterprise Network
Control Network
Field Site Field Site Field Site
PartnerSite
VPN
VPNFW
FW
IPS
IDS
IT Stuff
Scan
AV
FWIPS
P1711
FWAV
Host IPS Host AVProxy
Host IDS Host AV
IDS
Scan NAC
NAC 62351
Log Mgmt
Event Mgmt
Reporting
50000 Foot View
IT Stuff
VPN
ACM CCS Tutorial
Nov. 2009
Security Issues in
Industrial Control Systems
Availability, Integrity and Confidentiality
• Enterprise networks require C-I-A– Confidentiality of intellectual property matters most
• ICS requires A-I-C– Availability and integrity of control matters most– control data has low entropy—little need for confidentiality– Many ICS vendors provide six 9’s of availability
• Ensuring availability is hard– Cryptography does not help (directly)– DOS protection, rate limiting, resource management, QoS,
redundancy, robust hardware with high MTBF
• Security must not reduce availability!
DoS and DDoS Attacks
• Denial of Service (DoS) attack overwhelms a system with too many packets/requests– Exhausts TCP stack or application resources– Defenses include connection limits in firewall
• Distributed Denial of Service (DDoS) attack coordinates a botnet to overwhelm a target system– No single point of attack– Requires sophisticated, coordinated defenses– Weapon of choice for hackers, hacktivists, cyber-extortionists
• DoS, DDoS particularly effective when Availability is critical, i.e. against ICS
Fragile ICS Devices
• Many IP stack implementations are fragile– Some devices lockup on ping sweep or NMAP scan– Numerous incidents of ICS shut down by uninformed IT staff
running a well-intentioned vulnerability scan
• Modern ICS devices are much more complex– Some IEDs include web server for configuration and status– More lines of code leads to more bugs– Modern IEDs require patching just like servers
Unpatched Systems
• Many ICS systems are not patched current– Particularly Windows servers– No patches available for older versions of windows
• OS and application patches can break ICS– OS patches are tested for enterprise apps
• Uncertified patches can invalidate warranty• Patching often requires system reboot• Before installation of a patch:
– Vendor certification—typically one week– Lab testing by operator– Staged deployment on less critical systems first– Avoid interrupting any critical process phases
Limited use of Host Anti-Virus
• AV operations can cause significant system disruption at inopportune times– 3am is no better than any other time for a full disk scan on a
system that operates 24x7x365
• ICS vendors only beginning to support anti-virus– Anti-virus is only as good as the signature set– Signatures may require testing just like patches
• AV may be losing ground in enterprise deployments– impact on hosts, endpoint security not getting better– virus writers have learned to test against dominant AV
• application whitelisting can be a good alternative– enumerate goodness rather than badness
Poor Authentication and Authorization
• Machine-to-machine comms involve no “user”• Many ICS have poor authentication mechanisms
and very limited authorization mechanisms• Many protocols use cleartext passwords• Many ICS devices lack crypto support• Sometimes passwords left at vendor default• Device passwords are hard to manage appropriately
– Often one password is shared amongst all devices and all users and seldom if ever changed
– This is happening AGAIN in Smart Meter deployments!
Poor Audit and Logging
• Many ICS have poor or non-existent support for logging security-related actions– Attempted or successful intrusions may go unnoticed
• Where IDS logs are kept, they are often not reviewed• Various regulatory requirements are driving some
change in this area– NERC—North American Electric Reliability Corporation– FERC—Federal Energy Regulatory Commission– Sarbanes Oxley and PCAOB (Public Company Accounting
Oversight Board)– FISMA—Federal Information Security Management Act
Unmanned Field Sites
• Many unmanned field sites• Many with dialup access• Some with high-speed connectivity to control center• Most with poor authentication and authorization
backdoor to the control center!
Legacy Equipment
• Much legacy equipment• Usually impossible to update to add security features• Difficult to protect legacy communications
– but see IEEE P1711 for serial encryption
• Password protection is weak• Little or no audit and logging
Unauthorized Applications
• Unauthorized apps installed on ICS systems can interfere with ICS operation
• Many types of unauthorized apps have been found during security audits– Instant messaging– P2P file sharing– DVD and MPEG video players– Games, including Internet-based– Web browsers
Inappropriate Use of ICS Desktops
• Web browsing from HMI can infect ICS – Browser vulnerabilities– Downloads– Cross-site scripting– Spyware
• Email to/from control servers can infect ICS– Sendmail and outlook vulnerabilities
• Disk storage exhaustion can crash OS– Storage of music, videos
Little or No Cyber Security Monitoring
• internal monitoring is essential to detect low profile compromises– IDS– port scanning– vulnerability scanning– system audit
• without internal monitoring don’t know whether systems have been compromised
Requirement for 3rd Party Access
• Firmware updates and PLC, IED programming are sometimes done by vendor– Many ICS have open maintenance ports– Infected vendor laptops can bring down ICS
• Partners may require continuous status information– Partner access is often poorly secured– Partner channels can serve as backdoors
• 3rd parties may include:– ISO, transmission provider or grid neighbor,
equipment vendor, emissions monitoring service or agency, water level monitoring agency, vibration monitoring service, etc.
People Issues
• ICS network often managed by “Control Systems Department”, distinct from “IT Department” running enterprise network– ICS personnel are not IT or networking experts– IT personnel are not ICS experts
• Majority of control systems workforce is older and nearing retirement– Few young people entering this field– Few academic programs
Harsh Environments
• Temperature
• Vibration
• Dust
• Humidity
• Electrical Transients
Attack Vectors into Control Systems
Includes Infected Laptops and Is Growing
Source: 2003–2006 data from Eric Byres, BCIT
Security Assessments on ICS
• Various groups perform security assessments and penetration tests on ICS (generally under NDA)– Idaho National Labs– Sandia National Labs– N-Dimension Solutions– Other private organizations
• Vulnerability assessments always uncover problems• For penetration tests, we always get in
– Not a question of “if”, but “how long”
Other Issues
• Unusual physical topologies• Many special purpose, limited function devices• Static network configurations• Multicast• Long service lifetimes
For More Information ...
• See Smart Grid Cyber Security Strategy and Requirements, NISTIR 7628, www.nist.gov/smartgrid– particularly Appendices C and D
ACM CCS Tutorial
Nov. 2009
Today’s Threats
Hiroshima, 2.0 – Cyberspying of theUS Electric Grid (April 09)
Cyberspies penetrate electrical grid (April 09)
'Smart Grid' vulnerable to hackers (March 09)
CIA: Hackers Have Attacked Foreign Utilities (Jan 2008)
President Obama: securing the electric infrastructure is a national security priority (June 09)
Smart Grid Security Frenzy: Cyber War Games, Worms and Spies in Smart Grid (June 09)
earth2tech.com
Intense Media Visibility on the Cyber Security Issue
Limited Information About Incidents
• Little information sharing about actual attacks– BCIT incident database has about 30 incidents per year vs.
100s of thousands of incidents per year in CERT database– Few cyber attacks on ICS for which details are public
• Little information sharing about actual vulnerabilities– some are not easily or rapidly fixed– assessments are done under NDA
• Difficult to estimate risk– Difficult to demonstrate ROI for security spending
• But… lots of data about significant financial losses in enterprise and e-commerce– Why would control systems be immune?
Accidents Happen ...
Attacks Can Cause Similar Results
INL National Lab Aurora Demonstration, March 2007
Regulators provide Smart Grid Stimulus Funding criteria - cyber security is mandatory (June 09)
FERC releases Smart Grid Policy - cyber security mandatory for Utility rate recovery (July 09)
Strengthened Cyber Security Standards Approved for North American Utilities (May 09)
AMI-SEC working group developed security requirements for AMI
AMI-SEC Task Force
NIST developing interoperability and security standards for Smart Grid
Ontario Green Energy Act Drives Smart Grid With Security (May 09)
Cyber Security Regulatory Requirements
ACM CCS Tutorial
Nov. 2009
SecuringControl Systems
Adversaries
• Script kiddies• Hackers• Organized crime• Disgruntled insiders• Competitors• Terrorists• Hactivists• Eco-terrorists• Nation states
How an Attack Proceeds—Step #1
Internet
Modem Pool
Web Server
Email Server
BusinessWorkstation
DataHistorian
EngineeringWorkstation
FEPRTU Control
SystemNetwork
EnterpriseNetwork
Database Server
Domain NameServer (DNS)
enterpriseFirewall
ICSFirewall
Attacker
IED
IED
Web Server
Management Console HMI
How an Attack Proceeds—Step #2
Internet
Modem Pool
Web Server
BusinessWorkstation
DataHistorian
EngineeringWorkstation
FEPRTU Control
SystemNetwork
EnterpriseNetwork
Domain NameServer (DNS)
enterpriseFirewall
ICSFirewall
Attacker
IED
IED
Web Server
Management Console HMI
Email Server
Database Server
How an Attack Proceeds—Step #3
Internet
Modem Pool
Web Server
BusinessWorkstation
DataHistorian
EngineeringWorkstation
FEPRTU Control
SystemNetwork
EnterpriseNetwork
Domain NameServer (DNS)
enterpriseFirewall
ICSFirewall
Attacker
IED
IED
Web Server
Management Console HMI
Email Server
Database Server
How an Attack Proceeds—Step #4
Internet
Modem Pool
Web Server
Web Server
BusinessWorkstation
DataHistorian
Management Console HMI
EngineeringWorkstation
FEPRTU Control
SystemNetwork
EnterpriseNetwork
Domain NameServer (DNS)
enterpriseFirewall
ICSFirewall
Attacker
IED
IED
Vendor Web ServerEmail
Server
Database Server
How an Attack Proceeds—Step #5
Internet
Modem Pool
Web Server
Web Server
BusinessWorkstation
DataHistorian
Management Console HMI
EngineeringWorkstation
FEPRTU Control
SystemNetwork
EnterpriseNetwork
Domain NameServer (DNS)
enterpriseFirewall
ICSFirewall
Attacker
IED
IED
Vendor Web ServerEmail
Server
Database Server
How an Attack Proceeds—Step #6
Internet
Modem Pool
Web Server
Web Server
BusinessWorkstation
DataHistorian
Management Console HMI
EngineeringWorkstation
FEPRTU Control
SystemNetwork
EnterpriseNetwork
Domain NameServer (DNS)
enterpriseFirewall
ICSFirewall
Attacker
IED
IED
Email Server
Database Server
How an Attack Proceeds—Step #7
Internet
Modem Pool
Web Server
Web Server
BusinessWorkstation
DataHistorian
Management Console HMI
EngineeringWorkstation
FEPRTU Control
SystemNetwork
EnterpriseNetwork
Domain NameServer (DNS)
enterpriseFirewall
ICSFirewall
Attacker
IED
Email Server
IED
Database Server
Defending ICS
• Separate control network from enterprise network– Harden connection to enterprise network– Protect all points of entry with strong authentication– Make reconnaissance difficult from outside
• Harden interior of control network– Make reconnaissance difficult from inside– Avoid single points of vulnerability– Frustrate opportunities to expand a compromise
• Harden field sites and partner connections– mutual distrust
• Monitor both perimeter and inside events• Periodically scan for changes in security posture
Internet
Enterprise Network
Control Network
Field Site Field Site Field Site
PartnerSite
VPN
VPNFW
FW
IPS
IDS
IT Stuff
Scan
AV
FWIPS
P1711
FWAV
Host IPS Host AVProxy
Host IDS Host AV
IDS
Scan NAC
NAC 62351
Log Mgmt
Event Mgmt
Reporting
50000 Foot View
IT Stuff
VPN
Logical Overlay on SP99 / Purdue Model of Control
Site Business Planning and Logistics Network
BatchControl
DiscreteControl
SupervisoryControl
HybridControl
SupervisoryControl
Enterprise Network
Patch Mgmt
Web Services Operations
AV Server
Application Server
Email, Intranet, etc.
ProductionControl
HistorianOptimizing
ControlEngineering
Station
ContinuousControl
Terminal Services
Historian (Mirror)
Site Operations and Control
Area Supervisory
Control
Basic Control
Process
ControlZone
EnterpriseZone
DMZ
Level 5
Level 3
Level 1
Level 0
Level 2
Level 4
HMI HMI
Logical Architecture
• Enterprise Zone contains typical business systems– Email, web, office apps, etc.
• DMZ provides business connectivity– Contains only non-critical systems that need access to both
Control and Enterprise Zones– Enforces separation between Enterprise and Control Zones– Consists of multiple functional sub-zones
• Separated by Firewall, IPS, Anti-Virus, etc.
• Control Zone demarcates critical control systems– Consists of multiple functional sub-zones
• Internally protected by Firewall, IDS, Anti-Virus, etc.
How NOT to connect Control / Enterprise
• Dual-homed server• Dual-homed server with Host IPS / AV• Router with packet filter ACLs• Two-port Firewall• Router + Firewall combination
• See NISCC Good Practice Guide on Firewall Deployment for SCADA and Process Control Networks, NISCC and BCIT, Feb 2005
Web Services Operations
ApplicationServer
HistorianMirror
DMZ
DMZ—Logical View
PatchMgmt
AVProxy
Terminal Services
No Direct Traffic
Emergency Disconnect
Emergency Disconnect
Multiple Functional Sub-Zones
VPN
IPS
Scan
FWAV
Host AV
Proxy
Host IPS
IDS
IDS
DMZ Design Principles
• DMZ contains non-critical systems• Multiple functional security sub-zones• Traffic between sub-zones undergoes firewall (& IPS or IDS)• DMZ is only path in/out of Control Zone• Default deny for all firewall interfaces• No direct traffic across DMZ• No control traffic to outside• Limited outbound traffic from Control Zone• Very limited inbound traffic to Control Zone• No common ports between outside & inside• Emergency disconnect at inside or outside• No network management from outside• Cryptographic VPN and Firewall to all 3rd party connections
DMZ Implementation (1)
DMZ LAN 3
DMZ LAN 4
DMZ LAN 2
NAT
RoutingFWIPS
SecurityApplianceWithMultiplePorts
DMZ/ControlInterconnect WAN/LAN
EnterpriseLAN
Anti-VirusProxy
Host IPS / Anti-virus
DMZ Implementation (2)
dot1qtrunkDMZ VLAN 3
DMZ VLAN 4
DMZ VLAN 2
NAT
RoutingFWIPSVLAN
SecurityAppliance
VLAN-capable L2 switch
DMZ/ControlInterconnect WAN/LAN
EnterpriseLAN
Anti-VirusProxy
Host IPS / Anti-virus
NOT L3!
DMZ Implementation
• Sub-zones implemented by physical LANs or VLANs– Physical LANs require multi-port Security Appliance– VLANs require:
• VLAN-capable Security Appliance and Switch• anti-VLAN hopping protections on switch and FW• NO L3 (routing) on switch
• FW implements policy between– DMZ LANs, Enterprise Zone, Control Zone
• Anti-virus proxy controls outbound HTTP and/or FTP access to enterprise or Internet resources
• Host IPS and/or Host Anti-virus protects DMZ servers
Remote Access
DMZ
AAAServer
CertificateAuthority
Terminal Services
DMZ/ControlInterconnect WAN/LAN
EnterpriseLAN
Remote Access Pool
Remote Access
VPN
Remote Access
• Security Appliance terminates Host-to-site VPN into remote access pool– IPSEC VPN, SSL VPN, PPTP VPN
• Authenticates user via:– AAA server, LDAP, Active Directory, etc.– Can enforce use of multi-factor hardware token
• Time-varying password tokens for vendor access
• Clients use VNC, Citrix, or Remote Desktop (RDP) to connect to Terminal Server
• Then VNC, Citrix, RDP, or Control System Apps to Control System Servers
Control Zone—Logical View
BatchControl
DiscreteControl
SupervisoryControl
HybridControl
SupervisoryControl
ProductionControl
HistorianOptimizing
ControlEngineering
Station
ContinuousControl
Site Operations and Control
Area Supervisory
Control
Basic Control
Process
ControlZone
Level 3
Level 1
Level 0
Level 2HMI
HMI
DMZ
Control Zone Design Principles
• Multiple functional security sub-zones• Firewall and IDS between sub-zones• Minimal number of connections to DMZ• Control Zone independent of DMZ, Enterprise
– Separate Security Appliance from DMZ– Separate Time Server– Separate AAA– Allows emergency disconnect from DMZ
• Cryptographic VPN and Firewall to all offsite IP connections (Field Site or Partner)
• IEEE P1711 for all offsite serial ICS connections• Host IDS, Host AV, or app whitelisting where feasible• Management only from management zone
Control Zone Implementation—Hierarchical
• Fast routing between VLANs via L3 switch
• ACLs between VLANs but no Stateful Firewall
Level 1
Level 2
Level 3
ControlZone
dot1q Trunks
L3L3
L2 L2
QoS, Shaping, PolicingPort Security
Gigabit
10/100
DMZ/Control Interconnect WAN/LAN
SPANIDS
Scan
FWFW
Host IDS Host AV
Control Zone Implementation—Ring
• Ring reduces wiring for linear sites like power dams
• but spanning tree can have problems with large rings
Level 1
Level 2
Level 3
ControlZonedot1q Trunks
L3L3
L2 L2
QoS, Shaping, PolicingPort Security
Gigabit
10/100
DMZ/Control Interconnect WAN/LAN
SPANIDS
Scan
FWFW
Host IDS Host AV
FirewallIDS/IPS
Client VPN
ProxyNetwork AVHost IDS/IPS
NAC
Site-to-site VPN
DMZ
Perimeter Protection in Utilities
IDSPort ScanVuln Scan
FirewallNAC
SCADA VPN
FirewallSCADA VPN
Port ScanIDS
Interior Protection in Utilities
LogAnalyzeReport
Compliance
ManagedSecurity
Monitor, Log, Analyze, Report
• Planning, processes, procedures, physical security, etc. are also important
• NERC CIP Regulatory Requirements provide reasonably good guidance in this area:
• CIP-001: Sabotage Reporting• CIP-002: Critical Cyber Asset Identification• CIP-003: Security Management Controls• CIP-004: Personnel & Training• CIP-005: Electronic Security Perimeters• CIP-006: Physical Security• CIP-007: Systems Security Management• CIP-008: Incident Reporting & Response Planning• CIP-009: Recovery Plans for Critical Cyber Assets
See www.nerc.com -> Standards -> Reliability Standards -> CIP
Beyond Network Security
Summary
• Today’s ICS are mix of modern and legacy– vulnerabilities due to both
lack of security design in legacy and security issues in newer equipment
• Defense in depth is essential– both perimeter (DMZ) and
interior security are crucial
• Regulation and government action is driving change
• Smart Grid must be designed with strong security
ACM CCS Tutorial
Nov. 2009
Thanks!
andrew.wright@n-dimension.com
Standards Efforts
• NERC CIPs• NIST Smart Grid Interoperability Standards Project• NIST SP800-82• NIST SP800-53• NIST PCSRF Protection Profiles• AMI-SEC• ISA SP99• ODVA
• IEEE P1711 (AGA 12) -- serial SCADA encryption
A Few References
• www.nist.gov/smartgrid• Securing Your SCADA and Industrial Control
Systems, Version 1.0, DHS, ISBN 0-16-075115-8• Guide to SCADA and Industrial Control System
Security, NIST SP800-82• ISA99 Industrial Automation and Control Systems
Security, www.isa.org/MSTemplate.cfm?MicrositeID=988&CommitteeID=6821
• AGA 12/IEEE P1689 SCADA Encryption Standard, scadasafe.sf.net
Recommended