Cardiac Implant Flaw Patched, But Holes Remain

S4x17 CONFERENCE – Miami, Fla. – After more than four months of fallout over a controversial vulnerability disclosure by security firm MedSec on flaws it found in St. Jude Medical's cardiac implant products, the medical device vendor this week issued a security patch and the US Federal Drug Administration (FDA) published an alert that confirms vulnerabilities in the implant devices.

Healthcare security product and services firm MedSec has been in the hot seat since it licensed its vulnerability research of St. Jude Medical's cardiac implant devices to a financial trading firm that used the information to short-sell the stock of the medical device manufacturer – a move the firm says was meant to put pressure on St. Jude to fix the vulnerabilities. The short-sell tack raised eyebrows as an unorthodox way for MedSec to make money off its research, but MedSec contends that researchers are usually compensated for their work.

St. Jude Medical, which was acquired by Abbott Laboratories this month for $25 billion, in September filed a lawsuit against MedSec and Muddy Waters, claiming that they engaged in a "willful and malicious scheme to manipulate the securities markets for their own financial windfall."

In an interview here today with Dark Reading, Justine Bone, CEO of MedSec, says while her firm welcomes the security patch issued by St. Jude, the update doesn't address the full suite of flaws unearthed by her firm, and she expects more security updates to come from the manufacturer. "They've still got these underlying problems with a lack of authentication in the RF protocol that allows [potentially rogue] commands," for example, she says. That could allow an attacker to issue commands to the patient's implant to remotely shock it, or disable or drain its battery, she says.

The FDA on Monday officially warned that pacemakers made by St. Jude Medical were vulnerable to hacking via the manufacturer's Merlin@home Transmitter due to vulnerabilities in the device. St. Jude Medical, meanwhile, issued its patch, which is automatically applied to the devices when connected to the manufacturer's Merlin.net network.

"It's great to see St. Jude taking responsibility. They addressed and fixed one part of the problem, but a lot remain still untouched," Bone says. "These are critical problems."

St. Jude's patch addresses the vulnerability to a man-in-the-middle attack, Bone explains, via the Merlin infrastructure. "That was not our area of focus," she says, but jibes with authentication issues MedSec disclosed. Aside from authentication flaws, MedSec also found encryption and input validation vulnerabilities in its research, plus hardware flaws and exposed I/O ports.

Bone says MedSec decided not to disclose the flaws directly to St. Jude because it expected the firm would not remedy the issues. "I literally had people telling me they were shown the door" when trying to disclose bugs to St. Jude Medical, Bone says.

But MedSec didn't initially plan to bypass St. Jude. In an on-stage interview here with Digital Bond CEO Dale Peterson today, Bone said MedSec had planned to take the traditional disclosure route when it first embarked on a project to test various vendors' implant devices. "In the case of St. Jude, it was a very unusual situation … We were very confident that they would not acknowledge the vulnerabilities and not doing anything about it. We wanted to look for another route to hold St. Jude accountable, so we partnered with Muddy Waters," she said. "They [Muddy Waters] have a track history of holding large public companies accountable for other types of fraudulent behavior."

Even so, Bone says MedSec won't take the Muddy Waters-type route to disclosure again. "I have no intention of doing this again," she said. But she has no regrets, either: "It's an option that can be pursued" by researchers if needed, she said.

Peterson asked Bone about the ethics of profiting off the Muddy Waters report. Said Bone: "It's not unusual for researchers to be compensated for their work. It is unusual for a manufacturer to not act responsibly once it receives vulnerability" research, and profiting from faulty devices implanted in their patient customers, Bone said.

In an interview later with Dark Reading, Peterson says he believes MedSec wanted a way to monetize its research via the Muddy Waters disclosure. "I don't think there's anything wrong" with that, he says, but if a researcher decides to go that route, they should expect some "blowback."

MedSec handed the FDA and DHS ICS-CERT the vulnerability details when Muddy Waters published its report, Bone says. She says MedSec believes the combination of working with Muddy Waters, the FDA and DHS, helped prod St. Jude Medical to respond. "If we had only engaged with the FDA, for example, I'm not sure if St. Jude would have put the resources into understanding and responding to these issues," she says.

But critics say MedSec's bold disclosure method via Muddy Waters complicates an already fragile relationship between white-hat hackers and consumer device vendors still new to the bug disclosure scene. If interfacing directly with the device vendor isn't an option, researchers should work via the FDA and/or the ICS-CERT, says Josh Corman, director of the cyber statecraft initiative at the Atlantic Council.

"I can respect this might be a difficult company to deal with," Corman says. But then it's best to go through DHS or the FDA, he says. The FDA is the regulator of medical devices, so "St. Jude can't just blow off the FDA," he says.

Corman points out that St. Jude Medical is also one of the few medical device makers that has a vulnerability disclosure program in place. "In general, if a company has a disclosure program, I think it's our responsibility to use it."

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