Electrical Grid Is Called Vulnerable to Power Shutdown
By NICOLE PERLROTH
Two researchers discovered that they could freeze, or crash, the software
that monitors a substation, thereby blinding control center operators from
the power grid.
Over the past few months, the discoveries of two engineers have led to a
steady trickle of alarms from the Department of Homeland Security concerning
a threat to the nations power grid. Yet hardly anyone has noticed.
The
advisories
[copy below] concern vulnerabilities in the communication
protocol used by power and water utilities to remotely monitor control stations
around the country. Using those vulnerabilities, an attacker at a single,
unmanned power substation could inflict a widespread power outage.
Still, the two engineers who discovered the vulnerability say little is being
done.
Adam Crain and Chris Sistrunk do not specialize in security. The engineers
say they hardly qualify as security researchers. But seven months ago, Mr.
Crain wrote software to look for defects in an open-source software program.
The program targeted a very specific communications protocol called DNP3,
which is predominantly used by electric and water companies, and plays a
crucial role in so-called S.C.A.D.A. (supervisory control and data acquisition)
systems. Utility companies use S.C.A.D.A. systems to monitor far-flung power
stations from a control center, in part because it allows them to remotely
diagnose problems rather than wait for a technician to physically drive out
to a station and fix it.
Mr. Crain ran his security test on his open-source DNP3 program and didnt
find anything wrong. Frustrated, he tested a third-party vendors program
to make sure his software was working. The first program he targeted belonged
to Triangle MicroWorks, a Raleigh, North Carolina based company that sells
source code to large vendors of S.C.A.D.A. systems. It broke instantly.
Mr. Crain called Mr. Sistrunk, an electrical engineer, to see if he could
help Mr. Crain test his program on other systems.
When Adam told me he broke Triangle, I worried everything else was
broken, said Mr. Sistrunk.
Over the course of one week last April, the two tested Mr. Crains software
across 16 vendors systems. They did not find a single system they
couldnt break.
By the end of the week, the two had compiled a 20-page report replete with
vulnerabilities in 16 different system vendors for the Department of Homeland
Securitys Industrial Control Systems Cyber Emergency Response Team,
I.C.S.-C.E.R.T., which notifies vendors of vulnerabilities and issues public
advisories.
And then, they waited. It would take I.C.S.-C.E.R.T. another four months
to issue a public advisory for Triangle MicroWorks system.
Triangle MicroWorks engineering manager Greg Godlevski said that during
those four months, the company developed a number of its own tests to look
for defects in its software and fix them. Mr. Godlevski said the company
waited for confirmation from Mr. Crain that the problem had been fixed, then
met with I.C.S.-C.E.R.T. several times to review and comment on the government
advisory.
We take any reported problems discovered in our products very
seriously, Mr. Godlevski said. We expend a lot of effort adding
levels of security to our protocols and ensuring that they comply to the
published specifications.
D.H.S. did not return a request for comment.
Over the course of those four months, Mr. Crain and Mr. Sistrunk found
vulnerabilities in an additional nine vendors systems.
Like most security alerts, there are some caveats to this concern for the
safety of electric facilities: Mr. Petersons company, Digital Bond,
sells consulting services to assess and improve the security of S.C.A.D.A.
systems.
Mr. Crain also has an interest. In March, he plans to release a free version
of his security test, but for now he is charging vendors to use his program.
(Mr. Crain would not disclose pricing, since it differed for each vendor
based on vendor size, saying only that he charged in the thousands
though he said he charged far less than commercial services like WurldTech
Security, which charges tens of thousands of dollars for similar programs.)
We havent found anything we havent broken yet, Mr.
Crain said in an interview. At minimum, the two discovered that they could
freeze, or crash, the software that monitors a substation, thereby blinding
control center operators from the power grid. Mr. Crain likened that capability
to a bank robber being in a bank vault with the camera frozen.
In the case of one vendor, Mr. Crain found that he could actually infiltrate
a power stations control center from afar. An attacker could use that
capability to insert malware to take over the system, and like Stuxnet, the
computer worm that took out 20 percent of Irans centrifuges, inflict
actual physical harm.
This is low-hanging fruit, said Mr. Crain. It doesnt
require some kind of hacker mastermind to understand the protocol and do
this.
What makes the vulnerabilities particularly troubling, experts say, is that
traditional firewalls are ill-equipped to stop them. When the master
crashes it can no longer monitor or control any and all of the
substations, said Dale Peterson, a former N.S.A. employee who founded
Digital Bond, a security firm that focuses on infrastructure. There
is no way to stop this with a firewall and other perimeter security device
today. You have to let DNP3 responses through.
Even more troubling, Mr. Peterson said, is that most DNP3 communications
arent regulated. The original version of DNP3 worked on serial
communications a way of transmitting data usually found in things
like coaxial cables and is still widely deployed in large systems,
particularly substations around the country. But current cybersecurity
regulations, governed by the North American Electric Reliability
Corporations (N.E.R.C.) Critical Infrastructure Protection Committee
(C.I.P.C.) are focused on Internet Protocols, or I.P. protocols, and specifically
exclude serial communications and the equipment that uses them from meeting
any security requirements.
Why isnt D.H.S., N.E.R.C., and the DNP3 committee telling vendors
they need to fix this now and utility owners they need to get this patched
A.S.A.P.? Mr. Peterson said.
To date, D.H.S. has posted nine advisories, several of them for software
used by major players in the electric sector.
This is a systemic problem, Mr. Crain said. Most of the
top five utilities use this software and just because a patch is available,
doesnt necessarily mean that utilities are applying them.
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OVERVIEW
Adam Crain of Automatak and independent researcher Chris Sistrunk have identified
an improper input validation in the Alstom
e-terracontrol software. Alstom has produced a
patch that mitigates this vulnerability. Adam Crain and Chris Sistrunk have
tested the patch to validate that it resolves the vulnerability.
This vulnerability could be exploited remotely.
AFFECTED PRODUCTS
The following Alstom product is affected:
e-terracontrol, Version 3.5, 3.6, and 3.7.
IMPACT
Successful exploitation of this vulnerability could allow an attacker to
affect the availability of the Alstom
e-terracontrol software.
Impact to individual organizations depends on many factors that are unique
to each organization. ICSâCERT recommends that organizations
evaluate the impact of this vulnerability based on their operational environment,
architecture, and product implementation.
BACKGROUND
Alstom is a France-based company that maintains offices worldwide.
The affected product, Alstom e-terracontrol software,
is used on SCADA systems to monitor and control electrical energy systems.
According to Alstom, e-terracontrol software is
deployed across the electric energy sector. Alstom estimates that these products
are used primarily in the US and Europe with a small percentage in Asia.
The Alstom e-terracontrol software does not validate
or incorrectly validates input. An attacker could cause the software to go
into an infinite loop, causing the process to crash. The system must be restarted
manually to clear the condition.
CVE-2013-2787b has been assigned to this vulnerability.
A CVSS v2 base score of 7.1 has been assigned; the CVSS vector string is
(AV:N/AC:M/Au:N/C:N/I:N/A:C).c
VULNERABILITY DETAILS
EXPLOITABILITY
This vulnerability could be exploited remotely.
EXISTENCE OF EXPLOIT
No known public exploits specifically target this vulnerability.
DIFFICULTY
An attacker with a moderate skill level would be able to exploit this
vulnerability.
MITIGATION
Alstom has produced a patch that is available for download from the Alstom
Grid Customer Wise portal. Customers are encouraged to contact their Alstom
representative for download information.
ICSâCERT encourages asset owners to take additional defensive
measures to protect against this and other cybersecurity risks.
Minimize network exposure for all control system devices. Critical devices
should not directly face the Internet.
Locate control system networks and remote devices behind firewalls, and isolate
them from the business network.
When remote access is required, use secure methods, such as Virtual Private
Networks (VPNs), recognizing that VPN is only as secure as the connected
devices.
In addition, the researchers' suggest the following mitigations:
Block DNP3 traffic from traversing onto business or corporate networks through
the use of an IPS or firewall with DPN3-specific rule sets.
ICS-CERT also provides a section for control systems security recommended
practices on the ICS-CERT Web page. Several recommended practices are available
for reading and download, including Improving Industrial Control Systems
Cybersecurity with Defense-in-Depth
Strategies.d ICSâCERT reminds organizations
to perform proper impact analysis and risk assessment prior to taking defensive
measures.
Additional mitigation guidance and recommended practices are publicly available
in the ICSâCERT Technical Information Paper,
ICS-TIP-12-146-01BâTargeted Cyber Intrusion Detection and
Mitigation
Strategies,e that is available for download from the ICS-CERT
Web page
(http://ics-cert.us-cert.gov/).
Organizations observing any suspected malicious activity should follow their
established internal procedures and report their findings to
ICSâCERT for tracking and correlation against other incidents.