Critical Infrastructure Protection: Challenges and Efforts to
Secure Control Systems (30-MAR-04, GAO-04-628T).
Computerized control systems perform vital functions across many
of our nation's critical infrastructures. For example, in natural
gas distribution, they can monitor and control the pressure and
flow of gas through pipelines. In October 1997, the President's
Commission on Critical Infrastructure Protection emphasized the
increasing vulnerability of control systems to cyber attacks. At
the request of the House Committee on Government Reform,
Subcommittee on Technology, Information Policy, Intergovernmental
Relations and the Census, this testimony will discuss GAO's March
2004 report on potential cyber vulnerabilities, focusing on (1)
significant cybersecurity risks associated with control systems
(2) potential and reported cyber attacks against these systems
(3) key challenges to securing control systems, and (4) efforts
to strengthen the cybersecurity of control systems.
-------------------------Indexing Terms-------------------------
REPORTNUM: GAO-04-628T
ACCNO: A09652
TITLE: Critical Infrastructure Protection: Challenges and
Efforts to Secure Control Systems
DATE: 03/30/2004
SUBJECT: Computer crimes
Computer security
Computer software
Computer viruses
Criminals
Hackers
Information technology
Internal controls
National preparedness
Standards and standardization
Computer networks
Homeland security
******************************************************************
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GAO-04-628T
United States General Accounting Office
GAO Testimony
Before the Subcommittee on Technology Information Policy,
Intergovernmental Relations and the Census, House Committee on Government
Reform
For Release on Delivery Expected at 2 p.m. EST Tuesday, March 30, 2004
CRITICAL INFRASTRUCTURE PROTECTION
Challenges and Efforts to Secure Control Systems
Statement of Robert F. Dacey, Director, Information Security Issues
GAO-04-628T
This is a work of the U.S. government and is not subject to copyright
protection in the United States. It may be reproduced and distributed in
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separately.
Highlights of GAO-04-628T, a testimony before the Subcommittee on
Technology, Information Policy, Intergovernmental Relations and the
Census, House Committee on Government Reform
Computerized control systems perform vital functions across many of our
nation's critical infrastructures. For example, in natural gas
distribution, they can monitor and control the pressure and flow of gas
through pipelines. In October 1997, the President's Commission on Critical
Infrastructure Protection emphasized the increasing vulnerability of
control systems to cyber attacks. At the request of the House Committee on
Government Reform, Subcommittee on Technology, Information Policy,
Intergovernmental Relations and the Census, this testimony will discuss
GAO's March 2004 report on potential cyber vulnerabilities, focusing on
(1) significant cybersecurity risks associated with control systems (2)
potential and reported cyber attacks against these systems (3) key
challenges to securing control systems, and (4) efforts to strengthen the
cybersecurity of control systems.
In a March 2004 report, GAO recommends that the Secretary of the
Department of Homeland Security (DHS) develop and implement a strategy for
coordinating with the private sector and other government agencies to
improve control system security, including an approach for coordinating
the various ongoing efforts to secure control systems. DHS concurred with
GAO's recommendation.
www.gao.gov/cgi-bin/getrpt?GAO-04-628T.
To view the full product, including the scope and methodology, click on
the link above. For more information, contact Robert F. Dacey at (202)
512-3317 or [email protected].
March 30, 2004
CRITICAL INFRASTRUCTURE PROTECTION
Challenges and Efforts to Secure Control Systems
In addition to general cyber threats, which have been steadily increasing,
several factors have contributed to the escalation of the risks of cyber
attacks against control systems. These include the adoption of
standardized technologies with known vulnerabilities and the increased
connectivity of control systems to other systems. Typical control system
components are illustrated in the graphic below. Control systems can be
vulnerable to a variety of attacks, examples of which have already
occurred. Successful attacks on control systems could have devastating
consequences, such as endangering public health and safety.
Securing control systems poses significant challenges, including limited
specialized security technologies and lack of economic justification. The
government, academia, and private industry have initiated efforts to
strengthen the cybersecurity of control systems. The President's National
Strategy to Secure Cyberspace establishes a role for DHS to coordinate
with these entities to improve the cybersecurity of control systems. While
some coordination is occurring, DHS's coordination of these efforts could
accelerate the development and implementation of more secure systems.
Without effective coordination of these efforts, there is a risk of
delaying the development and implementation of more secure systems to
manage our critical infrastructures.
Typical Components of a Control System
Source: GAO (analysis), Art Explosion (clipart).
Mr. Chairman and Members of the Subcommittee:
I am pleased to be here today to participate in the Subcommittee's hearing
on the cyber vulnerabilities in industrial control systems. Control
systems-which include supervisory control and data acquisition (SCADA)
systems and distributed control systems1-perform vital functions across
many of our nation's critical infrastructures, including electric power
generation, transmission, and distribution; oil and gas refining and
pipelines; water treatment and distribution; chemical production and
processing; railroads and mass transit; and manufacturing. In October
1997, the President's Commission on Critical Infrastructure Protection
highlighted the risk of cyber attacks as a specific point of vulnerability
in our critical infrastructures, stating that "the widespread and
increasing use of SCADA systems for control of energy systems provides
increasing ability to cause serious damage and disruption by cyber means."
In my testimony today I will discuss the results of our recent report,
which is being released today.2 As you requested, this report identifies
(1) significant cybersecurity risks associated with control systems, (2)
potential and reported cyber attacks against these systems, (3) key
challenges to securing control systems, and (4) efforts to strengthen the
cybersecurity of control systems.
In preparing our report, we analyzed research studies and reports, as well
as prior GAO reports and testimonies on critical infrastructure protection
(CIP), information security, and national preparedness, among others. We
analyzed documents from and met with private-sector and federal officials
who had expertise in control systems and their security. Our work was
performed from July 2003 to March 2004 in accordance with generally
accepted government auditing standards.
1Control systems are computer-based systems that are used by many
infrastructures and industries to monitor and control sensitive processes
and physical functions. Typically, control systems collect sensor
measurements and operational data from the field, process and display this
information, and relay control commands to local or remote equipment.
There are two primary types of control systems. Distributed Control
Systems (DCS) typically are used within a single processing or generating
plant or over a small geographic area. Supervisory Control and Data
Acquisition (SCADA) systems typically are used for large, geographically
dispersed distribution operations.
2U.S. General Accounting Office, Critical Infrastructure Protection:
Challenges and Efforts to Secure Control Systems, GAO-04-354 (Washington,
D.C.: March 15, 2004).
Results in Brief
For several years, security risks have been reported in the control
systems on which many of the nation's critical infrastructures rely to
monitor and control sensitive processes and physical functions. In
addition to a steady increase in general cyber threats, several factors
have contributed to the escalation of risks specific to control systems,
including the (1) adoption of standardized technologies with known
vulnerabilities, (2) connectivity of control systems with other networks,
(3) insecure remote connections, and (4) widespread availability of
technical information about control systems.
Control systems can be vulnerable to a variety of types of cyber attacks
that could have devastating consequences-such as endangering public health
and safety; damaging the environment; or causing a loss of production,
generation, or distribution by public utilities. Control systems have
already been subject to a number of cyber attacks, including attacks on a
sewage treatment system in Australia in 2000 and, more recently, on a
nuclear power plant in Ohio.
Securing control systems poses significant challenges. These include the
limitations of current security technologies in securing control systems,
the perception that securing control systems may not be economically
justifiable, and conflicting priorities within organizations regarding the
security of control systems.
Government, academia, and private industry have initiated several efforts
that are intended to improve the security of control systems. These
initiatives include efforts to promote the research and development of new
technologies, the development of requirements and standards, an increased
awareness and sharing of information, and the implementation of effective
security management programs. The President's National Strategy to Secure
Cyberspace establishes a role for the Department of Homeland Security
(DHS) to coordinate with the private sector and other governments to
improve the cybersecurity of control systems. While some coordination is
occurring, DHS's coordination of these efforts could accelerate the
development and implementation of more secure systems. Without adequate
coordination of these efforts, there is a risk of delaying the development
and implementation of more secure systems to manage our critical
infrastructures.
In our March report, we recommend that the Secretary of DHS develop and
implement a strategy for coordinating with the private sector and
other government agencies to improve control system security, including
developing an approach for coordinating the various ongoing efforts to
secure control systems. This strategy should also be addressed in the
comprehensive national infrastructure plan that the department is tasked
to complete by December 2004. DHS's concurred with our recommendation and
agreed that improving the security of control systems against cyberattack
is a high priority.
Background
Cyberspace Introduces Risks for Control Systems
Dramatic increases in computer interconnectivity, especially in the use of
the Internet, continue to revolutionize the way our government, our
nation, and much of the world communicate and conduct business. The
benefits have been enormous. Vast amounts of information are now literally
at our fingertips, facilitating research on virtually every topic
imaginable; financial and other business transactions can be executed
almost instantaneously, often 24 hours a day, and electronic mail,
Internet Web sites, and computer bulletin boards allow us to communicate
quickly and easily with an unlimited number of individuals and groups.
However, this widespread interconnectivity poses significant risks to the
government's and our nation's computer systems and, more important, to the
critical operations and infrastructures they support. For example,
telecommunications, power distribution systems, water supplies, public
health services, national defense (including the military's warfighting
capability), law enforcement, government services, and emergency services
all depend on the security of their computer operations. If they are not
properly controlled, the speed and accessibility that create the enormous
benefits of the computer age may allow individuals and organizations to
eavesdrop on or interfere with these operations from remote locations for
mischievous or malicious purposes, including fraud or sabotage. Table 1
summarizes the key threats to our nation's infrastructures, as observed by
the Federal Bureau of Investigation (FBI).
Table 1: Threats to Critical Infrastructures Observed by the FBI
Threat Description
Criminal groups There is an increased use of cyber intrusions by criminal
groups who attack systems for monetary gain.
Foreign intelligence services Foreign intelligence services use cyber
tools as part of their information gathering and espionage activities.
Hackers Hackers sometimes crack into networks for the thrill of the
challenge or for bragging rights in the hacker community. While remote
cracking once required a fair amount of skill or computer knowledge,
hackers can now download attack scripts and protocols from the Internet
and launch them against victim sites. Thus, while attack tools have become
more sophisticated, they have also become easier to use.
Hacktivists Hacktivism refers to politically motivated attacks on publicly
accessible Web pages or e-mail servers. These groups and individuals
overload e-mail servers and hack into Web sites to send a political
message.
Information warfare Several nations are aggressively working to develop
information warfare doctrine, programs, and capabilities. Such
capabilities enable a single entity to have a significant and serious
impact by disrupting the supply, communications, and economic
infrastructures that support military power-impacts that, according to the
Director of Central Intelligence, can affect the daily lives of
a
Americans across the country.
Insider threat The disgruntled organization insider is a principal source
of computer crimes. Insiders may not need a great deal of knowledge about
computer intrusions because their knowledge of a victim system often
allows them to gain unrestricted access to cause damage to the system or
to steal system data. The insider threat also includes outsourcing
vendors.
Virus writers Virus writers are posing an increasingly serious threat.
Several destructive computer viruses and "worms" have harmed files and
hard drives, including the Melissa macro virus, the Explore.Zip worm, the
CIH (Chernobyl) virus, Nimda, and Code Red.
Source: Federal Bureau of Investigation, unless otherwise indicated.
aPrepared statement of George J. Tenet, Director of Central Intelligence,
before the Senate Select Committee on Intelligence, February 2, 2000.
Government officials remain concerned about attacks from individuals and
groups with malicious intent, such as crime, terrorism, foreign
intelligence gathering, and acts of war. According to the FBI, terrorists,
transnational criminals, and intelligence services are quickly becoming
aware of and using information exploitation tools such as computer
viruses, Trojan horses, worms, logic bombs, and eavesdropping sniffers
that can destroy, intercept, degrade the integrity of, or deny access to
data.3 In addition, the disgruntled organization insider is a significant
threat, because these individuals often have knowledge about the
organization and its system that allows them to gain unrestricted access
and inflict damage or steal assets without knowing a great deal about
computer intrusions. As larger amounts of money and more sensitive
economic and commercial information are exchanged electronically, and as
the nation's defense and intelligence communities increasingly rely on
standardized information technology (IT), the likelihood increases that
information attacks will threaten vital national interests.
As the number of individuals with computer skills has increased, more
intrusion or "hacking" tools have become readily available and relatively
easy to use. A hacker can download tools from the Internet and literally
"point and click" to start an attack. Experts agree that there has been a
steady advance in the level of sophistication and effectiveness of attack
technology. Intruders quickly develop attacks to exploit vulnerabilities
that have been discovered in products, use these attacks to compromise
computers, and share them with other attackers. In addition, they can
combine these attacks with other forms of technology to develop programs
that automatically scan networks for vulnerable systems, attack them,
compromise them, and use them to spread the attack even further.
From 1995 through 2003, the CERT Coordination Center4 (CERT/CC)
reported 12,946 security vulnerabilities that resulted from software
flaws. Figure 1 illustrates the dramatic growth in security
vulnerabilities over these years. The growing number of known
vulnerabilities increases the potential for attacks by the hacker
community. Attacks can be launched against specific targets or widely
distributed through viruses and worms.
3Virus: a program that "infects" computer files, usually executable
programs, by inserting a copy of itself into the file. These copies are
usually executed when the "infected" file is loaded into memory, allowing
the virus to infect other files. Unlike the computer worm, a virus
requires human involvement (usually unwitting) to propagate. Trojan horse:
a computer program that conceals harmful code. A Trojan horse usually
masquerades as a useful program that a user would wish to execute. Worm:
an independent computer program that reproduces by copying itself from one
system to another across a network. Unlike computer viruses, worms do not
require human involvement to propagate. Logic bomb: in programming, a form
of sabotage in which a programmer inserts code that causes the program to
perform a destructive action when some triggering event occurs, such as
termination of the programmer's employment. Sniffer: synonymous with
packet sniffer. A program that intercepts routed data and examines each
packet in search of specified information, such as passwords transmitted
in clear text.
4The CERT/CC is a center of Internet security expertise at the Software
Engineering Institute, a federally funded research and development center
operated by Carnegie Mellon University.
Figure 1: Security Vulnerabilities, 1995-2003
Along with these increasing vulnerabilities, the number of computer
security incidents reported to CERT/CC has also risen dramatically-from
9,859 in 1999 to 82,094 in 2002 and to 137,529 in 2003. And these are only
the reported attacks. The Director of the CERT Centers has estimated that
as much as 80 percent of actual security incidents goes unreported, in
most cases because (1) there were no indications of penetration or attack,
(2) the organization was unable to recognize that its systems had been
penetrated, or (3) the organization was reluctant to report. Figure 2
shows the number of incidents that were reported to the CERT/CC from 1995
through 2003.
Figure 2: Computer Security Incidents, 1995-2003
According to the National Security Agency (NSA), foreign governments
already have or are developing computer attack capabilities, and potential
adversaries are developing a body of knowledge about U.S. systems and
methods to attack these systems. The National Infrastructure Protection
Center (NIPC) reported in January 2002 that a computer belonging to an
individual who had indirect links to Osama bin Laden contained computer
programs that indicated that the individual was interested in the
structural engineering of dams and other water-retaining structures. The
NIPC report also stated that U.S. law enforcement and intelligence
agencies had received indications that Al Qaeda members had sought
information about control systems from multiple Web sites, specifically on
water supply and wastewater management practices in the United States and
abroad.
Since the terrorist attacks of September 11, 2001, warnings of the
potential for terrorist cyber attacks against our critical infrastructures
have increased. For example, in his February 2002 statement for the Senate
Select Committee on Intelligence, the Director of Central Intelligence
discussed the possibility of a cyber warfare attack by terrorists.5 He
stated that the September 11 attacks demonstrated the nation's dependence
on critical infrastructure systems that rely on electronic and computer
networks. Further, he noted that attacks of this nature would become an
increasingly viable option for terrorists as they and other foreign
adversaries become more familiar with these targets and the technologies
required to attack them. James Woolsey, a former Director of Central
Intelligence, shares this concern, and on October 29, 2003, in a speech
before several hundred security experts, he warned that the nation should
be prepared for continued terrorist attacks on our critical
infrastructures. Moreover, a group of concerned scientists warned
President Bush in a letter that "the critical infrastructure of the United
States, including electrical power, finance, telecommunications, health
care, transportation, water, defense and the Internet, is highly
vulnerable to cyber attack. Fast and resolute mitigating action is needed
to avoid national disaster." According to a study by a computer security
organization, during the second half of 2003, critical infrastructure
industries such as power, energy, and financial services experienced high
attack rates.6 Further, a study that surveyed over 170 security
professionals and other executives concluded that, across industries,
respondents believe that a large-scale cyber attack in the United States
will be launched against their industry by mid-2006.
What Are Control Systems?
Control systems are computer-based systems that are used within many
infrastructures and industries to monitor and control sensitive processes
and physical functions. Typically, control systems collect sensor
measurements and operational data from the field, process and display this
information, and relay control commands to local or remote equipment. In
the electric power industry, control systems can manage and control the
generation, transmission, and distribution of electric power- for example,
by opening and closing circuit breakers and setting thresholds for
preventive shutdowns. Employing integrated control systems, the oil and
gas industry can control the refining operations at a plant site, remotely
monitor the pressure and flow of gas pipelines, and control the flow and
pathways of gas transmission. Water utilities can
5Testimony of George J. Tenet, Director of Central Intelligence, before
the Senate Select Committee on Intelligence, February 6, 2002.
6Symantec, Symantec Internet Security Threat Report: Trends for July 1,
2003-December 31, 2003 (March 2004).
remotely monitor well levels and control the wells' pumps; monitor flows,
tank levels, or pressure in storage tanks; monitor water quality
characteristics-such as pH, turbidity, and chlorine residual; and control
the addition of chemicals. Control systems also are used in manufacturing
and chemical processing. Control systems perform functions that vary from
simple to complex; they can be used simply to monitor processes- for
example, the environmental conditions in a small office building-or to
manage most activities in a municipal water system or even a nuclear power
plant.
In certain industries, such as chemical and power generation, safety
systems are typically implemented in order to mitigate a potentially
disastrous event if control and other systems should fail. In addition, to
guard against both physical attack and system failure, organizations may
establish backup control centers that include uninterruptible power
supplies and backup generators.
There are two primary types of control systems. Distributed Control
Systems (DCS) typically are used within a single processing or generating
plant or over a small geographic area. Supervisory Control and Data
Acquisition (SCADA) systems typically are used for large, geographically
dispersed distribution operations. For example, a utility company may use
a DCS to generate power and a SCADA system to distribute it. Figure 3
illustrates the typical components of a control system.
monitoring station typically is connected to local controller stations
through a hard-wired network or to a remote controller station through a
communications network-which could be the Internet, a public switched
telephone network, or a cable or wireless (e.g., radio, microwave, or
Wi-Fi7) network. Each controller station has a remote terminal unit (RTU),
a programmable logic controller (PLC), or some other controller that
communicates with the supervisory control and monitoring station.
The control system also includes sensors and control equipment that
connect directly with the working components of the infrastructure-for
example, pipelines, water towers, or power lines. The sensor takes
readings from the infrastructure equipment-such as water or pressure
levels, electrical voltage or current-and sends a message to the
controller. The controller may be programmed to determine a course of
action and send a message to the control equipment instructing it what to
do-for example, to turn off a valve or dispense a chemical. If the
controller is not programmed to determine a course of action, the
controller communicates with the supervisory control and monitoring
station and relays instructions back to the control equipment. The control
system also can be programmed to issue alarms to the operator when certain
conditions are detected. Handheld devices, such as personal digital
assistants, can be used to locally monitor controller stations. Experts
report that technologies in controller stations are becoming more
intelligent and automated and are able to communicate with the supervisory
central monitoring and control station less frequently, thus requiring
less human intervention.
Control Systems Are at Increasing Risk
Historically, security concerns about control have been related primarily
to protecting them against physical attack and preventing the misuse of
refining and processing sites or distribution and holding facilities.
However, more recently, there has been a growing recognition that control
systems are now vulnerable to cyber attacks from numerous sources,
including hostile governments, terrorist groups, disgruntled employees,
and other malicious intruders.
In October 1997, the President's Commission on Critical Infrastructure
Protection discussed the potential damaging effects on the electric power
7Wi-Fi (short for wireless fidelity) is the popular term for a
high-frequency wireless local area network.
and oil and gas industries of successful attacks on control systems.8
Moreover, in 2002, the National Research Council identified "the potential
for attack on control systems" as requiring "urgent attention."9 In the
first half of that year, security experts reported that 70 percent of
energy and power companies experienced at least one severe cyber attack.
In February 2003, the President clearly demonstrated concern about "the
threat of organized cyber attacks capable of causing debilitating
disruption to our Nation's critical infrastructures, economy, or national
security," noting that "disruption of these systems can have significant
consequences for public health and safety" and emphasizing that the
protection of control systems has become "a national priority."10
Several factors have contributed to the escalation of risk to control
systems, including (1) the adoption of standardized technologies with
known vulnerabilities, (2) the connectivity of control systems to other
networks, (3) insecure remote connections, and (4) the widespread
availability of technical information about control systems.
Control Systems Are Adopting Standardized Technologies with Known
Vulnerabilities
In the past, proprietary hardware, software, and network protocols made it
difficult to understand how control systems operated-and therefore how to
hack into them. Today, however, to reduce costs and improve performance,
organizations have been transitioning from proprietary systems to less
expensive, standardized technologies such as Microsoft's Windows,
Unix-like operating systems, and the common networking protocols used by
the Internet. These widely-used, standardized technologies have commonly
known vulnerabilities, and sophisticated and effective exploitation tools
are widely available and relatively easy to use. As a consequence, both
the number of people with the knowledge to wage attacks and the number of
systems subject to attack have increased. Also, common communication
protocols and the emerging use of extensible markup language (commonly
referred to as XML) can make it easier for a hacker to interpret the
content of communications among the components of a control system.
8President's Commission on Critical Infrastructure Protection, Critical
Foundations: Protecting America's Infrastructures (Washington, D.C.:
October 1997).
9The National Research Council, Making the Nation Safer: the Role of
Science and Technology in Countering Terrorism (Washington, D.C.: December
2002).
10The White House, The National Strategy to Secure Cyberspace (Washington,
D.C.: February 2003).
Control Systems Are Connected to Other Networks
Enterprises often integrate their control systems with their enterprise
networks. This increased connectivity has significant advantages,
including providing decision makers with access to real-time information
and allowing engineers to monitor and control the process control system
from different points on the enterprise network. In addition, the
enterprise networks are often connected to the networks of strategic
partners and to the Internet. Furthermore, control systems are
increasingly using wide area networks and the Internet to transmit data to
their remote or local stations and individual devices. This convergence of
control networks with public and enterprise networks potentially creates
further security vulnerabilities in control systems. Unless appropriate
security controls are deployed in both the enterprise network and the
control system network, breaches in enterprise security can affect the
operation of control systems.
Insecure Connections Exacerbate Vulnerabilities
Vulnerabilities in control systems are exacerbated by insecure
connections. Organizations often leave access links-such as dial-up modems
to equipment and control information-open for remote diagnostics,
maintenance, and examination of system status. If such links are not
protected with authentication or encryption, the risk increases that
hackers could use these insecure connections to break into remotely
controlled systems. Also, control systems often use wireless
communications systems, which are especially vulnerable to attack, or
leased lines that pass through commercial telecommunications facilities.
Without encryption to protect data as it flows through these insecure
connections or authentication mechanisms to limit access, there is little
to protect the integrity of the information being transmitted.
Information about Infrastructures and Control Systems Is Publicly
Available
Public information about infrastructures and control systems is readily
available to potential hackers and intruders. The availability of this
infrastructure and vulnerability data was demonstrated last year by a
George Mason University graduate student who, in his dissertation,
reportedly mapped every business and industrial sector in the American
economy to the fiber-optic network that connects them, using material that
was available publicly on the Internet-and not classified.
In the electric power industry, open sources of information-such as
product data and educational videotapes from engineering associations- can
be used to understand the basics of the electrical grid. Other publicly
available information-including filings of the Federal Energy Regulatory
Commission (FERC), industry publications, maps, and material available on
the Internet-is sufficient to allow someone to identify the most heavily
loaded transmission lines and the most critical substations in the power
grid. Many of the electric utility officials who were interviewed for the
National Security Telecommunications Advisory Committee's Information
Assurance Task Force's Electric Power Risk Assessment expressed concern
over the amount of information about their infrastructure that is readily
available to the public.
In addition, significant information on control systems is publicly
available-including design and maintenance documents, technical standards
for the interconnection of control systems and RTUs, and standards for
communication among control devices-all of which could assist hackers in
understanding the systems and how to attack them. Moreover, there are
numerous former employees, vendors, support contractors, and other end
users of the same equipment worldwide who have inside knowledge about the
operation of control systems.
Security experts have stated that an individual with very little knowledge
of control systems could gain unauthorized access to a control system
using a port scanning tool and a factory manual that can be easily found
on the Internet and that contains the system's default password. As noted
in the following discussion, many times these default passwords are never
changed.
Cyber Threats to Control Systems
There is a general consensus-and increasing concern-among government
officials and experts on control systems about potential cyber threats to
the control systems that govern our critical infrastructures. As
components of control systems increasingly make vital decisions that were
once made by humans, the potential effect of a cyber attack becomes more
devastating. Cyber threats could come from numerous sources ranging from
hostile governments and terrorist groups to disgruntled employees and
other malicious intruders. Based on interviews and discussions with
representatives from throughout the electric power industry, the
Information Assurance Task Force of the National Security
Telecommunications Advisory Committee concluded that an organization with
sufficient resources, such as a foreign intelligence service or a
wellsupported terrorist group, could conduct a structured attack on the
electric power grid electronically, with a high degree of anonymity, and
without having to set foot in the target nation.
In July 2002, NIPC reported that the potential for compound cyber and
physical attacks, referred to as "swarming attacks," was an emerging
threat to the critical infrastructure of the United States. As NIPC
reports, the effects of a swarming attack include slowing or complicating
the response to a physical attack. For instance, a cyber attack that
disabled the water supply or the electrical system, in conjunction with a
physical attack, could deny emergency services the necessary resources to
manage the consequences of the physical attack-such as controlling fires,
coordinating response, and generating light.
According to the National Institute of Standards and Technology (NIST),
cyber attacks on energy production and distribution systems-including
electric, oil, gas, and water treatment, as well as on chemical plants
containing potentially hazardous substances-could endanger public health
and safety, damage the environment, and have serious financial
implications such as loss of production, generation, or distribution by
public utilities; compromise of proprietary information; or liability
issues. When backups for damaged components are not readily available
(e.g., extra-high-voltage transformers for the electric power grid), such
damage could have a long-lasting effect. I will now discuss potential and
reported cyber attacks on control systems, as well as challenges to
securing them.
Control Systems Can Be Vulnerable to Cyber Attacks
Entities or individuals with malicious intent might take one or more of
the following actions to successfully attack control systems:
o disrupt the operation of control systems by delaying or blocking the
flow of information through control networks, thereby denying availability
of the networks to control system operators;
o make unauthorized changes to programmed instructions in PLCs, RTUs, or
DCS controllers, change alarm thresholds, or issue unauthorized commands
to control equipment that could potentially result in damage to equipment
(if tolerances are exceeded), premature shutdown of processes (such as
prematurely shutting down transmission lines), or even disabling control
equipment;
o send false information to control system operators either to disguise
unauthorized changes or to initiate inappropriate actions by system
operators;
o modify the control system software, producing unpredictable results;
and
o interfere with the operation of safety systems.
In addition, in control systems that cover a wide geographic area, the
remote sites often are not staffed and may not be physically monitored. If
such remote systems were to be physically breached, attackers could
establish a cyber connection to the control network.
Department of Energy (DOE) and industry researchers have speculated on how
the following potential attack scenario could affect control systems in
the electricity sector. Using war dialers11 to find modems connected to
the programmable circuit breakers of the electric power control system,
hackers could crack passwords that control access to the circuit breakers
and could change the control settings to cause local power outages and
even damage equipment. A hacker could lower settings from, for example,
500 amperes12 to 200 on some circuit breakers; normal power usage would
then activate, or "trip," the circuit breakers, taking those lines out of
service and diverting power to neighboring lines. If, at the same time,
the hacker raised the settings on these neighboring lines to 900 amperes,
circuit breakers would fail to trip at these high settings, and the
diverted power would overload the lines and cause significant damage to
transformers and other critical equipment. The damaged equipment would
require major repairs that could result in lengthy outages.
Control system researchers at DOE's national laboratories have developed
systems that demonstrate the feasibility of a cyber attack on a control
system at an electric power substation where high-voltage electricity is
transformed for local use. Using tools that are readily available on the
Internet, they are able to modify output data from field sensors and take
control of the PLC directly in order to change settings and create new
output. These techniques could enable a hacker to cause an outage, thus
incapacitating the substation.
Experts in the water industry consider control systems to be among the
primary vulnerabilities of drinking water systems. A technologist from the
water distribution sector has demonstrated how an intruder could hack into
the communications channel between the control center of a water
distribution pump station and its remote units, located at water storage
11War dialers are simple personal computer programs that dial consecutive
phone numbers looking for modems.
12An ampere is a unit of measurement for electric current.
and pumping facilities, to either block messages or send false commands to
the remote units. Moreover, experts are concerned that terrorists could,
for example, trigger a cyber attack to release harmful amounts of water
treatment chemicals, such as chlorine, into the public's drinking water.
Cyber Attacks on Control Systems Have Been Reported
Experts in control systems have verified numerous incidents that have
affected control systems. Reported attacks include the following:
o In 1994, the computer system of the Salt River Project, a major water
and electricity provider in Phoenix, Arizona, was breached.
o In March 1997, a teenager in Worcester, Massachusetts, remotely
disabled part of the public switching network, disrupting telephone
service for 600 residents and the fire department and causing a
malfunction at the local airport.
o In the spring of 2000, a former employee of an Australian company that
develops manufacturing software applied for a job with the local
government, but was rejected. Over a 2-month period, the disgruntled
rejected employee reportedly used a radio transmitter on as many as 46
occasions to remotely hack into the controls of a sewage treatment system
and ultimately release about 264,000 gallons of raw sewage into nearby
rivers and parks.
o In the spring of 2001, hackers mounted an attack on systems that were
part of a development network at the California Independent System
Operator, a facility that is integral to the movement of electricity
throughout the state.
o In August 2003, the Nuclear Regulatory Commission confirmed that in
January 2003, the Microsoft SQL Server worm-otherwise known as
Slammer-infected a private computer network at the Davis-Besse nuclear
power plant in Oak Harbor, Ohio, disabling a safety monitoring system for
nearly 5 hours. In addition, the plant's process computer failed, and it
took about 6 hours for it to become available again. Slammer reportedly
also affected communications on the control networks of at least five
other utilities by propagating so quickly that control system traffic was
blocked.
In addition, in 1997, the Department of Defense (DOD) undertook the first
systematic exercise to determine the nation's and DOD's vulnerability to
cyberwar. During a 2-week military exercise known as Eligible Receiver,
staff from NSA used widely available tools to show how to penetrate the
control systems that are associated with providers of electric power to
DOD installations. Other assessments of control systems at DOD
installations have demonstrated vulnerabilities and identified risks in
the installations' network and operations.
Securing Control Systems Poses Significant Challenges
The control systems community faces several challenges to securing control
systems against cyber threats. These challenges include (1) the
limitations of current security technologies in securing control systems,
(2) the perception that securing control systems may not be economically
justifiable, and (3) the conflicting priorities within organizations
regarding the security of control systems.
Lack of Specialized Security Technologies for Control Systems
According to industry experts, existing security technologies, as well as
strong user authentication and patch management practices, are generally
not implemented in control systems because control systems usually have
limited processing capabilities, operate in real time, and are typically
not designed with cybersecurity in mind.
Existing security technologies13 such as authorization, authentication,
encryption, intrusion detection, and filtering of network traffic and
communications, require more bandwidth, processing power, and memory than
control system components typically have. Controller stations are
generally designed to do specific tasks, and they often use low-cost,
resource-constrained microprocessors. In fact, some control system devices
still use the Intel 8088 processor, which was introduced in 1978.
Consequently, it is difficult to install current security technologies
without seriously degrading the performance of the control system.
For example, complex passwords and other strong password practices are not
always used to prevent unauthorized access to control systems, in part
because this could hinder a rapid response to safety procedures during an
emergency. As a result, according to experts, weak passwords that are easy
to guess, shared, and infrequently changed are reportedly common in
control systems, including the use of default passwords or even no
password at all.
13 See U.S. General Accounting Office, Information Security: Technologies
to Secure Federal Systems, GAO-04-467 (Washington, D.C.: March 9, 2004)
for a discussion of cybersecurity technologies.
In addition, although modern control systems are based on standard
operating systems, they are typically customized to support control system
applications. Consequently, vendor-provided software patches may be either
incompatible with the customized version of the operating system or
difficult to implement without compromising service by shutting down
"always-on" systems or affecting interdependent operations. Another
constraint on deploying patches is that support agreements with control
system vendors often require the vendor's approval before the user can
install patches. If a patch is installed in violation of the support
agreement, the vendor will not take responsibility for potential impacts
on the operations of the system. Moreover, because a control system vendor
often requires that it be the sole provider of patches, if the vendor
delays in providing patches, systems remain vulnerable without recourse.
Information security organizations have noted that a gap exists between
currently available security technologies and the need for additional
research and development to secure control systems. Research and
development in a wide range of areas could lead to more effective
technologies. For example, although technologies such as robust firewalls
and strong authentication can be employed to better segment control
systems from external networks, research and development could help to
address the application of security technologies to the control systems
themselves. Other areas that have been noted for possible research and
development include identifying the types of security technologies needed
for different control system applications, determining acceptable
performance trade-offs, and recognizing attack patterns for use in
intrusion detection systems.
Industry experts have identified challenges in migrating system components
to newer technologies while maintaining uninterrupted operations.
Upgrading all the components of a control system can be a lengthy process,
and the enhanced security features of newly installed technologies-such as
their ability to interpret encrypted messages-may not be able to be fully
utilized until all devices in the system have been replaced and the
upgrade is complete.
Securing Control Systems May Not Be Perceived as Economically Justifiable
Experts and industry representatives have indicated that organizations may
be reluctant to spend more money to secure control systems. Hardening the
security of control systems would require industries to expend more
resources, including acquiring more personnel, providing
training for personnel, and potentially prematurely replacing current
systems, which typically have a lifespan of about 20 years.
Several vendors suggested that since there have been no reports of
significant disruptions caused by cyber attacks on U.S. control systems,
industry representatives believe the threat of such an attack is low.
While incidents have occurred, to date there is no formalized process for
collecting and analyzing information about control systems incidents, thus
further contributing to the skepticism of control systems vendors. We have
previously recommended that the government work with the private sector to
improve the quality and quantity of information being shared among
industries and government about attacks on the nation's critical
infrastructures.14
Until industry users of control systems have a business case to justify
why additional security is needed, there may be little market incentive
for the private sector to develop and implement more secure control
systems. We have previously reported that consideration of further federal
government efforts is needed to provide appropriate incentives for
nonfederal entities to enhance their efforts to implement CIP-including
protection of control systems. Without appropriate consideration of public
policy tools, such as regulation, grants, and tax incentives,
private-sector participation in sector-related CIP efforts may not reach
its full potential.15
Organizational Priorities Conflict
Finally, several experts and industry representatives indicated that the
responsibility for securing control systems typically includes two
separate groups: (1) IT security personnel and (2) control system
engineers and operators. IT security personnel tend to focus on securing
enterprise systems, while control system engineers and operators tend to
be more concerned with the reliable performance of their control systems.
These experts indicate that, as a result, those two groups do not always
fully understand each other's requirements and so may not effectively
collaborate to implement secure control systems.
14U.S. General Accounting Office, Critical Infrastructure Protection:
Challenges for Selected Agencies and Industry Sectors, GAO-03-233
(Washington, D.C.: Feb. 28, 2003).
15U.S. General Accounting Office, Homeland Security: Information Sharing
Responsibilities, Challenges, and Key Management Issues, GAO-03-1165T
(Washington, D.C.: Sept. 17, 2003).
These conflicting priorities may perpetuate a lack of awareness of IT
security strategies that could be deployed to mitigate the vulnerabilities
of control systems without affecting their performance. Although research
and development will be necessary to develop technologies to secure
individual control system devices, existing IT security technologies and
approaches could be implemented as part of a secure enterprise
architecture to protect the perimeters of, and access to, control system
networks. Existing IT security technologies include firewalls,
intrusiondetection systems, encryption, authentication, and authorization.
Approaches to IT security include segmenting control system networks and
testing continuity plans to ensure safe and continued operation.
To reduce the vulnerabilities of its control system, officials from one
company formed a team composed of IT staff, process control engineers, and
manufacturing employees. This team worked collaboratively to research
vulnerabilities and to test fixes and workarounds.
Efforts to Strengthen the Cybersecurity of Control Systems Under
Way, but Lack Adequate Coordination Government, academia, and private
industry have independently initiated multiple efforts and programs
focused on some of the key areas that should be addressed to strengthen
the cybersecurity of control systems. Our March 2004 report includes a
detailed discussion of many initiatives. The key areas-and illustrative
examples of ongoing efforts in these areas-include the following:
o Research and development of new security technologies to protect
control systems. Both federal and nonfederal entities have initiated
efforts to develop encryption methods for securing communications on
control system networks and field devices. Moreover, DOE is planning to
establish a National SCADA Test Bed to test control system
vulnerabilities. However, funding constraints have delayed the
implementation of the initial phases of these plans.
o Development of requirements and standards for control system security.
Several entities are working to develop standards that increase the
security of control systems. The North American Electric Reliability
Council (NERC) is preparing to draft a standard that will include security
requirements for control systems. In addition, the Process Controls
Security Requirements Forum (PCSRF), established by NIST and NSA, is
working to define a common set of information security requirements for
control systems. However, according to NIST officials, reductions to
fiscal year 2004 appropriations will delay these efforts.
o Increased awareness of security and sharing of information about the
implementation of more secure architectures and existing security
technologies. To promote awareness of control system vulnerabilities, DOE
has created security programs, trained teams to conduct security reviews,
and developed cybersecurity courses. The Instrumentation Systems and
Automation Society has reported on the known state of the art of
cybersecurity technologies as they are applied to the control systems
environment, to clearly define what technologies can currently be
deployed.
o Implementation of effective security management programs, including
policies and guidance that consider control system security. Both federal
and nonfederal entities have developed guidance to mitigate the security
vulnerabilities of control systems. DOE's 21 Steps to Improve Cyber
Security of SCADA Networks provides guidance for improving the security of
control systems and establishing underlying management processes and
policies to help organizations improve the security of control system
networks.
In previous reports, we have recommended the development of a
comprehensive and coordinated national plan to facilitate the federal
government's CIP efforts. This plan should clearly delineate the roles and
responsibilities of federal and nonfederal CIP entities, define interim
objectives and milestones, set time frames for achieving objectives, and
establish performance measures.
The President in his homeland security strategies and Congress in enacting
the Homeland Security Act designated DHS as responsible for developing a
comprehensive national infrastructure plan. The plan is expected to inform
DHS on budgeting and planning for CIP activities and on how to use policy
instruments to coordinate among government and private entities to raise
the security of our national infrastructures to appropriate levels.
According to Homeland Security Presidential Directive 7 (HSPD 7), issued
December 17, 2003, DHS is to develop this formalized plan by December
2004.
In February 2003, the President's National Strategy to Secure Cyberspace
established a role for DHS to coordinate with other government agencies
and the private sector to improve the cybersecurity of control systems.
DHS's assigned role includes:
o ensuring that there is broad awareness of the vulnerabilities in
control systems and the consequences of exploiting these vulnerabilities,
o developing best practices and new technologies to strengthen the
security of control systems, and
o identifying the nation's most critical control system sites and
developing a prioritized plan for ensuring cyber security at those sites.
In addition, the President's strategy recommends that DHS work with the
private sector to promote voluntary standards efforts and the creation of
security policy for control systems.
DHS recently began to focus on the range of activities that are under way
among the numerous entities that are working to address these areas. In
October 2003, DHS's Science and Technology Directorate initiated a study
to determine the current state of security of control systems. In December
2003, DHS established the Control Systems Section within the Protective
Security Division of its Information Analysis and Infrastructure
Protection (IAIP) Directorate. The objectives of this section are to
identify computercontrolled systems that are vital to infrastructure
functions, evaluate the potential threats to these systems, and develop
strategies that mitigate the consequences of attacks. In addition, IAIP's
National Cyber Security Division (NCSD) is planning to develop a
methodology for conducting cyber assessments across all critical
infrastructures, including control systems. The objectives of this effort
include defining specific goals for the assessments and, based on their
results, developing sector-specific recommendations to mitigate
vulnerabilities. NCSD also plans to examine processes, technology, and
available policy, procedures, and guidance. Because these efforts have
only recently been initiated, DHS acknowledges that it has not yet
developed a strategy for implementing the functions mentioned above.
As I previously mentioned, many government and nongovernment entities are
spearheading various initiatives to address the challenge of implementing
cybersecurity for the vital systems that operate our nation's critical
infrastructures. While some coordination is occurring, both federal and
nonfederal control systems experts have expressed their concern that these
efforts are not being adequately coordinated among government agencies,
the private sector, and standards-setting bodies. DHS's coordination of
these efforts could accelerate the development and implementation of more
secure systems to manage our critical infrastructures. In contrast,
insufficient coordination could contribute to
o delays in the general acceptance of security requirements and the
adoption of successful practices for control systems,
o failure to address gaps in the research and development of
technologies to better secure control systems,
o impediments to standards-creating efforts across industries that could
lead to less expensive technological solutions, and
o reduced opportunities for efficiency that could be gained by
leveraging ongoing work.
In summary, it is clear that the systems that monitor and control the
sensitive processes and physical functions of the nation's critical
infrastructures are at increasing risk from threats of cyber attacks.
Securing these systems poses significant challenges. Numerous federal
agencies, critical infrastructure sectors, and standards-creating bodies
are leading various initiatives to address these challenges. DHS's
implementation of our recommendation-with which the department
concurred-to develop and implement a strategy for better coordinating the
cybersecurity of our critical infrastructures' control systems among
government and private sector entities can accelerate progress in securing
these critical systems. Additionally, implementing existing IT
technologies and security approaches can strengthen the security of
control systems. These approaches include establishing an effective
security management program, building successive layers of defense
mechanisms at strategic access points to the control system network, and
developing and testing continuity plans to ensure safe operation in the
event of a power outage or cyber attack.
Mr. Chairman, this concludes my statement. I would be pleased to answer
any questions that you or other members of the Subcommittee may have at
this time.
If you should have any questions about this statement, please contact me
at (202) 512-3317 or Elizabeth Johnston, Assistant Director, at (202)
5126345. We can also be reached by e-mail at [email protected] and
[email protected], respectively.
Other individuals who made key contributors to this testimony include
Shannin Addison, Joanne Fiorino, Alison Jacobs, Anjalique Lawrence, and
Tracy Pierson.
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