Buggy 'smart meters' open door to power-grid botnet
Grid-burrowing worm only the beginning
New electricity meters being rolled out to millions of homes and businesses are riddled with security bugs that could bring down the power grid, according to a security researcher who plans to demonstrate several attacks at a security conference next month.
The so-called smart meters for the first time provide two-way communications between electricity users and the power plants that serve them. Prodded by billions of dollars from President Obama's economic stimulus package, utilities in Seattle, Houston, Miami, and elsewhere are racing to install them as part of a plan to make the power grid more efficient. Their counterparts throughout Europe are also spending heavily on the new technology.
There's just one problem: The newfangled meters needed to make the smart grid work are built on buggy software that's easily hacked, said Mike Davis, a senior security consultant for IOActive. The vast majority of them use no encryption and ask for no authentication before carrying out sensitive functions such as running software updates and severing customers from the power grid. The vulnerabilities, he said, are ripe for abuse.
"We can switch off hundreds of thousands of homes potentially at the same time," Davis, who has spent the past few months analyzing a half-dozen smart meters, told The Reg. "That starts providing problems that the power company may not be able to gracefully deal with."
To prove his point, Davis and his IOActive colleagues designed a worm that self-propagates across a large number of one manufacturer's smart meter. Once infected, the device is under the control of the malware developers in much the way infected PCs are under the spell of bot herders. Attackers can then send instructions that cause its software to turn power on or off and reveal power usage or sensitive system configuration settings.
The worm, which Davis will demonstrate next month at the Black Hat security conference in Las Vegas, is able to spread quickly. It exploits an automatic update feature in the meter that runs on peer-to-peer technology that doesn't use code signing or other measures to make sure the update is authorized. It uses a routine known as interrupt hooking, which adds additional code to the device's operating system.
'Kind of scary'
Davis declined to identify the model of the smart meter or its manufacturer, but he said most of the models he's examined suffer from the same poor design.
"For an embedded platform, they're kind of scary," he said. "It's really not designed from the ground up for security. Just imagine if somebody is outside your house and has the unique identifier that's printed on your meter."
One deficiency common among many of the meters is the use of insecure programming functions, such as memcpy() and strcpy(), which are two of the most common sources of exploitable software bugs. In many cases, the devices use general purpose hardware and software that aren't designed for highly targeted or mission critical systems.
By 2015, utilities in more than two-dozen US states expect to have almost 52 million customers outfitted with the bidirectional smart meters, according to this break-down (PDF) from the Edison Electric Institute, which represents power companies. Some of those deployments are already completed and many more will be completed in the next few years.
The new generation of meters will enable what utility companies call smart grids. They turn the power grid into a real-time computerized network, which has the ability to make automated decisions in real time based on data collected from millions of sensors. That would eliminate the need for meter readers to visit each customer to know how much electricity has been consumed, for instance.
But the potential of the smart grid goes well beyond that. Technicians envision a system that raises or lowers rates hour by hour depending on the supply of power available, which would be measured based on the reports of millions of individual meters. In some scenarios, smart meters would respond to power shortages by telling smart appliances such as clothes driers and dish washers to shut off until power is more plentiful.
"This is something that's been on everyone's radar," said Ed Legge, a spokesman for Edison Electric. "I think we've reached that point of opportunity plus ability to do it."
He said the rush to upgrade has only increased in the months following passage of Barack Obama's stimulus package, which reserved $4.5bn for smart-grid spending. To qualify, however, utilities must meet aggressive deadlines that have only accelerated companies' upgrade plans.
As a result, concerns about security have taken a back seat, said IOActive's Davis. Before the incentives were announced, several utilities approached him and asked if he would perform penetration tests on meters they planned to roll out.
"As soon as the stimulus bill came out, everybody just clammed up," he said. "It's almost impossible for us to get new devices to look at now."
Another problem with smart grids is that utilities are essentially responsible for policing themselves, said security consultant Tony Flick, who plans to offer a separate turbo talk at Black Hat. He likens the regulatory arrangement to that in the frequently criticized credit card industry, in which merchants are required only to comply with rules set by other companies in the industry.
"It's kind of like history repeating itself," he said. "They're being relied upon to actually implement the standards without any true oversight." ®