Critical Infrastructure Protection
Challenges and Efforts to Secure Control Systems Gao ID: GAO-04-628T March 30, 2004Computerized 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 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. 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.
GAO-04-628T, Critical Infrastructure Protection: Challenges and Efforts to Secure Control Systems
This is the accessible text file for GAO report number GAO-04-628T
entitled 'Critical Infrastructure Protection: Challenges and Efforts to
Secure Control Systems' which was released on March 30, 2004.
This text file was formatted by the U.S. General Accounting Office
(GAO) to be accessible to users with visual impairments, as part of a
longer term project to improve GAO products' accessibility. Every
attempt has been made to maintain the structural and data integrity of
the original printed product. Accessibility features, such as text
descriptions of tables, consecutively numbered footnotes placed at the
end of the file, and the text of agency comment letters, are provided
but may not exactly duplicate the presentation or format of the printed
version. The portable document format (PDF) file is an exact electronic
replica of the printed version. We welcome your feedback. Please E-mail
your comments regarding the contents or accessibility features of this
document to Webmaster@gao.gov.
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 its entirety without further permission from GAO. Because this work
may contain copyrighted images or other material, permission from the
copyright holder may be necessary if you wish to reproduce this
material separately.
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:
GAO Highlights:
Highlights of GAO-04-628T, a testimony before the Subcommittee on
Technology, Information Policy, Intergovernmental Relations and the
Census, House Committee on Government Reform
Why GAO Did This Study:
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.
What GAO Found:
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.
What GAO Recommends:
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 daceyr@gao.gov.
[End of section]
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 systems[Footnote 1]--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.[Footnote 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.
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: Criminal groups; Description: There is an increased use of
cyber intrusions by criminal groups who attack systems for monetary
gain.
Threat: Foreign intelligence services;
Description: Foreign intelligence services use cyber tools as part of
their information gathering and espionage activities.
Threat: Hackers;
Description: 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.
Threat: Hacktivists;
Description: 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.
Threat: Information warfare;
Description: 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
Americans across the country.[A].
Threat: Insider threat;
Description: 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.
Threat: Virus writers;
Description: 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.
[A] Prepared statement of George J. Tenet, Director of Central
Intelligence, before the Senate Select Committee on Intelligence,
February 2, 2000.
[End of table]
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.[Footnote 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 Center[Footnote 4]
(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.
Figure 1: Security Vulnerabilities, 1995-2003:
[See PDF for image]
[End of figure]
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:
[See PDF for image]
[End of figure]
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.[Footnote 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.[Footnote 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 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.
Figure 3: Typical Components of a Control System:
[See PDF for image]
[End of figure]
Note: Remote/local stations can include one or more interfaces to allow
field operators to perform diagnostic and maintenance operations.
Sensors can measure level, pressure, flow, current, voltages, etc.,
depending on the infrastructure. Control equipment can be valves,
pumps, relays, circuit breakers, etc., also depending on the
infrastructure.
A control system typically is made up of a "master" or central
supervisory control and monitoring station consisting of one or more
human-machine interfaces where an operator can view status information
about the remote/local sites and issue commands directly to the system.
Typically, this station is located at a main site, along with
application servers and an engineering workstation that is used to
configure and troubleshoot the other components of the control system.
The supervisory control and 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-Fi[Footnote 7]) 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 and oil and gas industries of successful attacks on control
systems.[Footnote 8] Moreover, in 2002, the National Research Council
identified "the potential for attack on control systems" as requiring
"urgent attention."[Footnote 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."[Footnote 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.
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 well-supported 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:
* 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;
* 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;
* send false information to control system operators either to disguise
unauthorized changes or to initiate inappropriate actions by system
operators;
* modify the control system software, producing unpredictable results;
and:
* 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 dialers[Footnote 11] 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 amperes[Footnote 12]
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 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:
* In 1994, the computer system of the Salt River Project, a major water
and electricity provider in Phoenix, Arizona, was breached.
* 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.
* 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.
* 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.
* 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 technologies[Footnote 13] 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.
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.[Footnote 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.[Footnote 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.
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, intrusion-detection 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:
* 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.
* 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.
* 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.
* 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:
* ensuring that there is broad awareness of the vulnerabilities in
control systems and the consequences of exploiting these
vulnerabilities,
* developing best practices and new technologies to strengthen the
security of control systems, and:
* 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 computer-controlled 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:
* delays in the general acceptance of security requirements and the
adoption of successful practices for control systems,
* failure to address gaps in the research and development of
technologies to better secure control systems,
* impediments to standards-creating efforts across industries that
could lead to less expensive technological solutions, and:
* 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) 512-6345. We can also be reached by e-mail at daceyr@gao.gov and
johnstone@gao.gov, respectively.
Other individuals who made key contributors to this testimony include
Shannin Addison, Joanne Fiorino, Alison Jacobs, Anjalique Lawrence, and
Tracy Pierson.
FOOTNOTES
[1] Control 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.
[2] U.S. General Accounting Office, Critical Infrastructure Protection:
Challenges and Efforts to Secure Control Systems, GAO-04-354
(Washington, D.C.: March 15, 2004).
[3] Virus: 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.
[4] The 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.
[5] Testimony of George J. Tenet, Director of Central Intelligence,
before the Senate Select Committee on Intelligence, February 6, 2002.
[6] Symantec, Symantec Internet Security Threat Report: Trends for July
1, 2003-December 31, 2003 (March 2004).
[7] Wi-Fi (short for wireless fidelity) is the popular term for a high-
frequency wireless local area network.
[8] President's Commission on Critical Infrastructure Protection,
Critical Foundations: Protecting America's Infrastructures
(Washington, D.C.: October 1997).
[9] The National Research Council, Making the Nation Safer: the Role of
Science and Technology in Countering Terrorism (Washington, D.C.:
December 2002).
[10] The White House, The National Strategy to Secure Cyberspace
(Washington, D.C.: February 2003).
[11] War dialers are simple personal computer programs that dial
consecutive phone numbers looking for modems.
[12] An ampere is a unit of measurement for electric current.
[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.
[14] U.S. General Accounting Office, Critical Infrastructure
Protection: Challenges for Selected Agencies and Industry Sectors,
GAO-03-233 (Washington, D.C.: Feb. 28, 2003).
[15] U.S. General Accounting Office, Homeland Security: Information
Sharing Responsibilities, Challenges, and Key Management Issues,
GAO-03-1165T (Washington, D.C.: Sept. 17, 2003).
