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Comment by jwcacces | Hacker News Reader

“These problems can’t be patched,” says Nohl, who will join Lell in presenting the research at the Black Hat security conference in Las Vegas. “We’re exploiting the very way that USB is designed.”

‘In this new way of thinking, you have to consider a USB infected and throw it away as soon as it touches a non-trusted computer.’

So now we need a USB abstinence campaign?

When you have a USB with someone, you are having a USB with everyone they had a USB with for the last ten years, and everyone they and their partners have had a USB with for the last ten years.

Also, we're just calling it a USB now? Not a USB thumbdrive, USB hard drive, or whatever? This article sounds like it was written by my mom.

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It most surely can be patched. Allow a USB device to offer up a signature that the PC can verify. The CA would be the manufacturer which has a private key for each USB key manufactured (so hackers can't steal one private key and copy it). Make sure the manufacturer revokes keys that are compromised. Bam, instant manufacturer guarantee that the hardware is genuine. That is, until the private key is uncovered by the hackers, but that's what expiration dates are for I suppose.

That will work in the same way that DVD copy protection worked - briefly and ineffectively.

It's not a good DRM protection. It is a reasonable way to verify hardware for a user though.

How would the manufacturer know that an individual thumb drive has been compromised?

The user would need to receive the equipment in some secure fashion. Direct from the manufacturer in tamper-proof packaging or something. And from there it's up to the user of the key to ensure it is not physically compromised.

How do you ensure that a malicious firmware is not just impersonating the valid firmware for the device?

With a signature

What prevents the firmware replaying a transaction with a valid signature? You're relying on the device to give you a true copy of the firmware it's running, but that means trusting something that's not trustworthy.

One could use some sort of RSA secure token technology that would be very hard to replicate the state of at the time of the attack. I guess my point is that there's loads of ways USB could be used in a secure fashion. To say it can't be "patched" is completely unfounded in reality.

The firmware on a USB stick should not be writeable.

When will you ever update the firmware on your storage device. Never, USB sticks are cheap and disposable. Mass produced ones should have their firmware burned into ROM.

This does nothing to protect you. Malicious users will just make their own usb stick. The parts aren't exactly expensive.

Of course it does something to protect me. It means that I can plug my USB drive into a friend's computer, then plug it back into my own computer without worry.

Only if you fully trust the entire supply chain down to you. Do you have any way to verify that the mass storage device you bought was not a forgery?

I'm not aiming for perfection, just aiming to improve. It is easier for me to trust that the sealed USB drive I bought has not been tampered with than it is for me to trust that all of my friends are knowledgeable and avoid malware.

yes I agree that this looks like a good step, vendors should also probably release some tools to verify the integrity of their firmwares if possible.

When? All the damned time. Maybe you have an external HD or SSD based on USB, updating the firmware is perfectly acceptable. Same thing for HIDs and NICs. High performance USB drives are basically little SSDs, and there's plenty of reasons for wanting to update the controller firmware on them to improve features or performance.

It should not, however, be generally possible for arbitrary programs to update the firmware on a USB device without both the consent of the computer host's current user/administrator AND the device's manufacturer (subject to certain hedges and caviats of course). Right now many USB devices are just wide open, allowing this chaos of security vulnerabilities, that should not be.

> So now we need a USB abstinence campaign?

What's your risk assessment?

Some places already have a USB abstinence campaign - they remove the ports and do as much as they can to remove the functionality from their OS. Or they remove as many ports as they can and lock other cables in place.

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