This is when viruses start getting scary...
http://www.securityfocus.com/news/6767
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Slammer worm crashed Ohio nuke plant network
By Kevin Poulsen, SecurityFocus Aug 19 2003 2:45PM
The Slammer worm penetrated a private computer network at Ohio's Davis-Besse
nuclear power plant in January and disabled a safety monitoring system
for nearly five hours, despite a belief by plant personnel that the network
was protected by a firewall, SecurityFocus has learned.
The breach did not post a safety hazard. The troubled plant had been offline
since February, 2002, when workers discovered a 6-by-5-inch hole in the
plant's reactor head. Moreover, the monitoring system, called a Safety
Parameter Display System, had a redundant analog backup that was unaffected
by the worm. But at least one expert says the case illustrates a growing
cybersecurity problem in the nuclear power industry, where interconnection
between plant and corporate networks is becoming more common, and is permitted
by federal safety regulations.
The Davis-Besse plant is operated by FirstEnergy Corp., the Ohio utility
company that's become the focus
The incident at the plant is described in an April e-mail to the Nuclear
Regulatory Commission (NRC) from FirstEnergy, and in a similarly-worded
March safety advisory distributed privately throughout the industry over
the "Nuclear Network," an information-sharing program run by
the Institute of Nuclear Power Operations. The March advisory was issued
to "alert the industry to consequences of Internet Worms and Viruses
on Plant Computer Systems," according to the text.
The reports paint a sobering picture of cybersecurity at FirstEnergy.
The Slammer worm entered the Davis-Besse plant through a circuitous route.
It began by penetrating the unsecured network of an unnamed Davis-Besse
contractor, then squirmed through a T1 line bridging that network and Davis-Besse's
corporate network. The T1 line, investigators later found, was one of multiple
ingresses into Davis-Besse's business network that completely bypassed
the plant's firewall, which was programmed to block the port Slammer used
to spread.
"This is in essence a backdoor from the Internet to the Corporate
internal network that was not monitored by Corporate personnel," reads
the April NRC filing by FirstEnergy's Dale Wuokko. "[S]ome people
in Corporate's Network Services department were aware of this T1 connection
and some were not."
Users noticed slow performance on Davis-Besse's business network at 9:00
a.m., Saturday, January 25th, at the same time Slammer began hitting networks
around the world. From the business network, the worm spread to the plant
network, where it found purchase in at least one unpatched Windows server.
According to the reports, plant computer engineers hadn't installed the
patch for the MS-SQL vulnerability that Slammer exploited. In fact, they
didn't know there was a patch, which Microsoft released six months before
Slammer struck.
Operators Burdened
By 4:00 p.m., power plant workers noticed a slowdown on the plant network.
At 4:50 p.m., the congestion created by the worm's scanning crashed the
plant's computerized display panel, called the Safety Parameter Display
System.
An SPDS monitors the most crucial safety indicators at a plant, like coolant
systems, core temperature sensors, and external radiation sensors. Many
of those continue to require careful monitoring even while a plant is offline,
says one expert. An SPDS outage lasting eight hours or more requires that
the NRC be notified.
At 5:13 p.m., another, less critical, monitoring system called the "Plant
Process Computer" crashed. Both systems had redundant analog backups
that were unaffected by the worm, but, "The unavailability of the
SPDS and the PPC was burdensome on the operators," notes the March
advisory.
It took four hours and fifty minutes to restore the SPDS, six hours and
nine minutes to get the PPC working again.
FirstEnergy declined to elaborate on the incident. The company has become
the focus of an investigation into last week's northeastern U.S. blackout.
Though the full cause of the blackout has yet to be determined, investigators
have reportedly found that it began when an Ohio high-voltage transmission
line "tripped" after sagging into a tree. An alarm system
that was part of FirstEnergy's Energy Management System failed to warn
operators at the company's control center that the line had failed.
Asked if last week's "Blaster" worm might have had a hand in
the alarm system failure, just as Slammer disabled the Davis-Besse safety
display panel, FirstEnergy spokesman Todd Schneider said, "We're investigating
everything right now."
"I have not heard of anything like that," added Schneider. "The
alarm system was the only system that was not functioning."
SCADA Issues
The Davis-Besse incident was not Slammer's only point of impact on the
electric industry. According to a document released
A SCADA (Supervisory Control and Data Acquisition) system consists of central
host that monitors and controls smaller Remote Terminal Units (RTUs) sprinkled
throughout a plant, or in the field at key points in an electrical distribution
network. The RTUs, in turn, directly monitor and control various pieces
of equipment.
In a second case reported in the same document, a power company's SCADA
traffic was blocked because it relied on bandwidth leased from a telecommunications
company that fell prey to the worm.
Reports on the effect of last week's Blaster worm on the electric grid,
if any, have yet to emerge.
The Slammer attacks came after years of warnings about the vulnerability
"[T]he distinct trend within the industry is to link the systems to
access control center data necessary for business purposes," reads
the report. "One utility interviewed considered the business value
of access to the data within the control center worth the risk of open
connections between the control center and the corporate network."
Future Safety Concerns
An energy sector cybersecurity expert who's reviewed nuclear plant networks,
speaking on condition of anonymity, said the trend of linking operations
networks with corporate LANs continues unabated within the nuclear energy
industry, because of the economic benefits of giving engineers easy access
to plant data. An increase in plant efficient of a
couple percentage points "can translate to millions upon millions
of dollars per year," says the expert.
He says Slammer's effect on Davis-Besse highlights the dangers of such
interconnectivity.
Currently, U.S. nuclear plants generally have digital systems monitoring
critical plant operations, but not controlling them, said the expert. But
if an intruder could tamper with monitoring systems like Davis-Besse's
SPDS, which operators are accustomed to trusting, that could increase the
risk of an accident.
Moreover, the industry is moving in the direction of installing digital
controls that would allow for remote operation of plant functions, perhaps
within a few years, if the NRC approves it. "This is absolutely unacceptable
without drastic changes to plant computer networks," says the expert.
"If a non-intelligent worm can get in, imagine what an
intruder can do."
Jim Davis, director of operations at the Nuclear Energy Institute, an industry
association, says those concerns are overblown. "If you break all
the connections and allow no data to pass from anywhere to anywhere, you've
got great security -- but why'd you put the digital systems in the first
place?," says Davis.
Davis says the industry learned from the Davis-Besse incident, but that
the breach didn't prove that connections between plant and corporate networks
can't be implemented securely. "You can put a well-protected read-only
capability on a data stream that provides you reasonable assurance that
nobody can come back down that line to the control
system," says Davis.
Last year the NEI formed a task force to develop updated cybersecurity
management guidelines for the industry. The results -- which will be secret
-- are expected within a few months. As part of a research effort earlier
this year, the NEI's task force worked with the NRC and a contractor to
review cybersecurity at four nuclear power plants. The details of the review
are classified as "Safeguards" material, but Davis says the investigation
found no serious problems. "There are no issues that generate a public
health and safety concern," says Davis.
"Sometime people get very anxious about digital systems and what you
could or couldn't do with digital systems, but in lots of cases you've
got switches and valves and little override buttons on this thing and that
thing that could cause a component to shut down as quickly as any digital
system," Davis says.
Despite the Slammer breach, FirstEnergy was apparently not in violation
of NRC's limited, and aging, cybersecurity regulations. For its part, the
commission wouldn't comment on the incident. The NRC has faced fierce criticism
for not acting sooner
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On Tuesday, September 2nd, 2003 by Tom Duff
