SCADA security vulnerability imperils critical water valves
Dec. 14, 2011
A small and very simple electronic device used to control complex machinery in water treatment plants, nuclear power generating stations and other critical industrial facilities contains serious security vulnerabilities that allow hackers and attackers to completely take over the infrastructure remotely, a U.S. agency that safeguards the nation's critical infrastructure has warned.
Certain models of the Modicon Quantum PLC (programmable logic controller) used in complex industrial control systems contain multiple hidden accounts that use predetermined, hard-coded passwords to grant full remote access, the Industrial Control System Cyber Emergency Response Team (ICSCERT) said in an advisory issued yesterday.
Schneider Electric, the maker of the PLC device, has produced numerous fixes for some of the security weaknesses and continues to develop additional mitigations, but the speed at which it produces the fixes may not be fast enough, according to some outside consultants.
The PLCs reside at the lowest levels of an industrial plant, where multiple computerized sensors work with the valves, turbines, and other machinery that's being controlled. The security issues reside in the default passwords that are hard-coded into Ethernet cards (NICs) the systems use to funnel commands into the devices, and temperatures and other data out of them.
The Ethernet modules also allow system administrators to remotely log into the machinery using totally insecure communications protocols such as telnet, FTP, and something called the Windriver Debug port.
According to a blog post published on Monday by independent security researcher Ruben Santamarta, the NOE 100 and the NOE 771 modules made by Schneider Electric contain at least 14 hard-coded passwords, some of which are widely published in support and technical manuals.
Even in cases where the passcodes are obscured using cryptographic hashes, they are trivial to recover thanks to documented weaknesses in the underlying VxWorks operating system. As a result, attackers can exploit the security vulnerabilities to log into critical and complex devices and gain full privileged access to its sensitive controls.
Hard-coded passwords are a common weakness built into many industrial control systems, including some S7 series of PLCs from Siemens in Germany. Because the systems control the machinery connected to electric power dams, oil and gasoline refineries, and water treatment plants, unauthorized access is considered a national security threat because it could be used to sabotage their operation, cause massive destruction, cause great risks to the environment and endanger the lives of millions of U.S. residents.
The FBI has said that it is investigating multiple claims that a Houston, Texas–based water utility was breached in November by someone claiming to have accessed the internet-connected computers that control its generators, blowers and other sensitive equipment.
“Default backdoor passwords that give you full administrator rights to a system are extremely severe,” said Reid Wightman, a security assessor with Digital Bond, a consultancy that focuses solely on ICS security. He said it can be hard for attackers to exercise too much control over an ICS by taking over the PLC alone, because there's often no indication what kind of equipment is connected to it.
“You don't have the human machine interface so you don't really know what the PLC is plugged into,” he explained. “I really don't know if the device is a release valve, an input valve, or a lightbulb or any other device for that matter.”
Research Wightman plans to release in January 2012 at the SCADA Security Scientific Symposium in Miami could increase the damage that attackers can do after gaining access to many widely used PLCs. Among other things, he said his findings would show how to tamper with the device so that they attack other systems they are attached to as well, further compounding the issue.
Santamarta added that the hard-coded passwords could be widely exploited to install malicious firmware on the controllers. He also alluded to non-documented functionalities with security implications in the Schneider devices. He said he initially discovered the hidden accounts by reverse engineering the firmware that controls the PLCs.
A rudimentary search on a search engine known as Shodan revealed what appears to be working links to several of the vulnerable Schneider models. Santamarta said there is no fix for the devices other than to retire the faulty Ethernet cards and replace them with better-designed ones.
Tuesday's ICS-CERT advisory said that the fixes from Schneider removes the telnet and Windriver services. The advisory made no mention of changes to FTP services or Telnet access, however.
In other internet security news
Police in the United Kingdom have confirmed that about 800 victims had their mobile phones hacked by journalists at the News of the World tabloid, after initial fears that the number of victims could top 5,800.
A Scotland Yard initial release said that investigators "are confident that we have personally contacted all the people who have been hacked or who are likely to have been hacked."
In November, investigators were saying they had identified 5,795 potential phone-hacking victims in the material collected from Glenn Mulcaire, the private investigator who was jailed in 2007.
Now those same investigators say they have interviewed 2,037 people, of whom about 803 are victims. Their names appeared in notes seized from Mulcaire, who had been working for Rupert Murdoch's News of the World.
Scotland Yard said yesterday that there are still many people who need to be interviewed, although it is unlikely they were hacking victims.
Murdoch closed the tabloid in July after it was revealed that the paper had hacked into the phone of a 13-year-old murder victim, Milly Dowler, in hopes of gathering material for news stories.
The scandal erupted after the Dowler disclosed that celebrities such as Sienna Miller, Hugh Grant and Jude Law had complained of being hacked. Even former British prime minister Gordon Brown complained to the police, who later found his name in Mulcaire's notes.
In the wake of the scandal, two top London police officers and several senior Murdoch executives resigned and more than a dozen News of the World journalists have been arrested, including former editor Andy Coulson, who resigned his post as Prime Minister David Cameron's media chief.
The News of the World paper has since folded, and the proceeds of the last week of revenues were donated to charity, a spokesman said.
In other mobile news
On Friday, scientists have managed to circumvent the encryption used to protect smartcards that are widely used to restrict access in corporate and government buildings, and to even process payments in public transit systems, something that makes it possible to clone perfect replicas of the digital keys and steal or modify their contents, representing a critical security issue.
Developed by researchers at Germany's Ruhr University, the exploit only takes about seven hours to recover the secret key protecting the Mifare DESFire MF3ICD-40 security encryption system. And the hack doesn't even leave a single trace that the card has been compromised, but its does require equipment costing upwards of $3,000, the group said.
The contactless card, which some customers adopted following the cracking of the Mifare Classic in 2008, is used by transit agencies in San Francisco, Australia, and the Czech Republic. It was also adopted by NASA in 2004, although it's not clear if the agency has since upgraded it to a more secure system.
The findings of researchers David Oswald and Christof Paar are the latest to shatter the protection in embedded electronic devices that millions of people rely on to secure homes, offices, and mobile payment accounts.
In addition to the breaking of the Mifare Classic, a team of scientists that included Paar also managed to successfully crack the encryption of the Keeloq security system used by manufacturers of cars, garage door openers, and other similar devices.
Like the previous two hacks, the latest attack recovered the card's secret key, allowing an adversary to assume the digital identity of individuals who use it to prove they are who they say they are.
NXP has marketed the DESFire MF3ICD40 despite its growing vulnerability to attack. "It provides a recipe for how to extract the secret key material non-invasively, basically by pointing a radio probe at the card and monitoring it as it performs a transaction," said cryptographer Nate Lawson, the principal of Root Labs, who has read the research.
"This is something that's easily replicable with a few thousand dollars and a little amount of time, so it's practical," he added.
Oswald and Paar's attack relied on side-channel analysis, a technique that records a device's electromagnetic radiation or other physical characteristics to learn important clues about the encryption taking place inside.
In much the way a safe cracker listens to pin clicks to figure out a vault's combination, their differential power analysis allows them to recover the 112-bit secret key that locks digital information stored on the DESFire card.
It also involves the use of a probe connected to an oscilloscope that records electrical emanations while the card is being read by an RFID, or radio-frequency identification, reader.
For the recovery to succeed, an attacker must first buy a DESFire card and spend months making detailed and careful observations about its smallest inner behaviors. It took the researchers about a year to "profile" their card, although Oswald said that a trained engineer could probably cut that time in half.
Using the findings in their paper, a hacker could probably save even more time off the profiling. With that task out of the way, all that's required for them to compromise a card is to have physical access to it for about seven hours.
Once they're done, they will have access to the secret key needed to clone the card and access or modify whatever data is stored on it. And the hack cannot be detected later either, something that's even more troubling.
Source: The Industrial Control System Cyber Emergency Response Team.
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