US warns nuke plants of worm threat

[InfoSec News <isn () c4i org>]

http://www.theregister.co.uk/content/56/32647.html

By Kevin Poulsen
SecurityFocus
Posted: 03/09/2003 

The U.S. Nuclear Regulatory Commission on Tuesday issued a formal
Information Notice to nuclear power plant operators warning them about
an incident in January in which the Slammer computer worm penetrated
networks at Ohio's Davis-Besse nuclear plant and disabled two
important monitoring systems for hours.

The notice is the NRC's first public acknowledgement of the incident,
which was first reported by SecurityFocus last month.

In a statement, the NRC said it issued the notice to warn utilities of
the potential for nuclear plants to be infected by the Slammer worm.  
But the commission emphasized that the Slammer-induced failures at
Davis-Besse did not affect the safe operation of the plant. "NRC
regulations require safety-related systems to be isolated or have
send-only communication with other systems," the commission said.

The notice follows a private industry advisory circulated last March,
and a similarly worded e-mail sent to the NRC in April by an official
at FirstEnergy Corp., the Ohio utility that runs the plant. "It just
went through the usual bureaucratic process," says NRC spokesman Scott
Burnell. "Once the investigations that FirstEnergy had done were
completed, they turned it over to us."

The worm entered the Davis-Besse plant by penetrating a contractor's
network, then squirming through a T1 line bridging that network and
Davis-Besse's corporate LAN. The T1 line, investigators later found,
completely bypassed the plant's firewall, which was programmed to
block the port Slammer used to spread.

 From the corporate network, the worm moved to the plant's operations
network, where the traffic jam it produced disabled a system called
the Plant Process Computer, and the Safety Parameter Display System --
a computerized display panel that monitors critical plant functions. A
redundant analog backup to the SPDS was unaffected by the worm.

The troubled plant had been offline since early 2002, when workers
discovered a 6-by-5-inch hole in the plant's reactor head.

The Information Notice includes no specific recommendations, and does
not address any danger posed by the more recent Blaster worm. But it
notes that the NRC issued a security order in February, 2002, alerting
plant operators to the possibility that external network
interconnections might improperly bypass protective measures, like
firewalls. At FirstEnergy, that security order was implemented by the
plant's IT personnel, but was not passed on to the plant computer
engineers responsible for the wayward T1 line, according to the
notice.

Plant computer engineers were also unaware that a patch was available
for the MS-SQL vulnerability that Slammer exploited. Microsoft had
released the patch six months earlier.

FirstEnergy has become a focus of the investigation into last month's
northeastern U.S. power outage.



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