Feeds

'Data storm' blamed for nuclear plant shutdown

Malfunctioning control device causes fatal spike in traffic

Internet Security Threat Report 2014

No digital contagion has been fingered in the latest incident, said Terry Johnson, spokesman for the Tennessee Valley Authority, the public power company that runs the Browns Ferry power plant.

"The integrated control system (ICS) network is not connected to the network outside the plant, but it is connected to a very large number of controllers and devices in the plant," Johnson said. "You can end up with a lot of information, and it appears to be more than it could handle."

The device responsible for flooding the network with data appears to be a programmable logic controller (PLC) connected to the plant's Ethernet network, according to an NRC information notice on the incident (PDF). The PLC controlled Unit 3's condensate demineralizer - essentially a water softener for nuclear plants. The flood of data spewed out by the malfunctioning controller caused the variable frequency drive (VFD) controllers for the recirculation pumps to hang.

Such failures are common among PLC and supervisory control and data acquisition (SCADA) systems, because the manufacturers do not test the devices' handling of bad data, said Dale Peterson, CEO of industrial system security firm DigitalBond.

"What is happening in this marketplace is that vendors will build their own (network) stacks to make it cheaper," Peterson said. "And it works, but when (the device) gets anything that it didn't expect, it will gag."

In many cases, a simple vulnerability scan will even cause the devices to crash, Peterson said. During tests in an electrical substation, Nessus running in safe scan mode crashed devices, he said. In some cases, sending out broadcast data on the network will crash several of connected devices, he added.

"If you were to test any control systems that have any more than three or four different network-connected devices, they could be knocked over very easily," Peterson said.

The Browns Ferry nuclear power plant has had its share of difficulties. All three units of the plant were shutdown in 1985 due to performance and management problems, according to the NRC. Unit 2 was restarted in 1991, and Unit 3 started operating again in 1995. On Tuesday, the NRC gave the Tennessee Valley Authority permission to restart Unit 1.

The Committee on Homeland Security gave the NRC until 14 June to respond to its letter.

This article originally appeared in Security Focus.

Copyright © 2007, SecurityFocus

Top 5 reasons to deploy VMware with Tegile

More from The Register

next story
'Regin': The 'New Stuxnet' spook-grade SOFTWARE WEAPON described
'A degree of technical competence rarely seen'
You really need to do some tech support for Aunty Agnes
Free anti-virus software, expires, stops updating and p0wns the world
You stupid BRICK! PCs running Avast AV can't handle Windows fixes
Fix issued, fingers pointed, forums in flames
Regin: The super-spyware the security industry has been silent about
NSA fingered as likely source of complex malware family
Privacy bods offer GOV SPY VICTIMS a FREE SPYWARE SNIFFER
Looks for gov malware that evades most antivirus
Patch NOW! Microsoft slings emergency bug fix at Windows admins
Vulnerability promotes lusers to domain overlords ... oops
HACKERS can DELETE SURVEILLANCE DVRS remotely – report
Hikvision devices wide open to hacking, claim securobods
prev story

Whitepapers

Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
10 threats to successful enterprise endpoint backup
10 threats to a successful backup including issues with BYOD, slow backups and ineffective security.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Protecting users from Firesheep and other Sidejacking attacks with SSL
Discussing the vulnerabilities inherent in Wi-Fi networks, and how using TLS/SSL for your entire site will assure security.