Jailbroken Devices Compromised By Charging Stations

mask.of.sanity writes "Data can be stolen from Windows, Android and Apple devices by unassuming power charging towers. In an attack demonstrated at the Defcon hacking conference, mobile phone charging units were rigged to pull data from phones plugged into them. Researchers found many jailbroken and modified devices activated USB functions when they were plugged in, or simply rebooted."

Comments

Hmm

[LocalH]

So basically, you connect an untrusted device to a device you trust somewhat, and you're shocked when bad things can happen?

It's like people who would pick up a random USB drive off the ground and then plug it into their computer without taking precautions. Why is this any different?

Re:Hmm

[Anonymous Coward]

I'm not sure if your USB drive example is a good comparison to this situation. Charging stations are being commonplace and showing up in airports, coffee shops, etc. Businesses that people trust.

I think think this is more like a fake ATM machine. People are so used to ATMs being everywhere, that little thought is given when they enter their PIN number into one. It's not something that the average person is going to think twice about.

Re:Hmm

[Em Adespoton]

Tell me this... does this amazing OS of yours alert you when you plug in a new USB keyboard? Because some of the USB sticks people find on the ground have both a flash memory partition and a fake keyboard interface that sends key commands in a predefined manner.

I'm all for OSes that fingerprint all your USB devices and require you to validate each function of each interface the first time presented, but even OpenBSD doesn't do this by default.

Seatback charging on airplanes

[mpoulton]

I flew on Air Canada a few weeks ago and they had USB ports for charging integrated into the seatback touchscreen displays. When I plugged my phone (HTC Incredible running CM7 nightlies) into it with a USB data cable, it indicated a valid data connection to a host controller! I was surprised and thought the seatback device probably contained a small PC to handle the interactive display. I tried to poke around on the host device to see what I could find, but didn't get anywhere with it. For some reason it didn't even occur to me that the "poking around" could be going the other way. If someone could compromise those seatback devices, the phone contents of thousands of passengers could be automatically collected...

Re:Seatback charging on airplanes

[Anonymous Coward]

AC Chargers that can supply up to 1000ma short the two data pins together to tell the phone it can draw that high amount of current.
USB devices connected to a controller are only allowed to draw 500ma, and only after negotiation with the host.
A USB connected to a port where the data pins are not shorted AND cannot negotiate a higher current with the host is only allowed to draw 100ma.

So removing the data pins from a USB port will prolong charge duration 5x or 10x

Re:Er... how can Android be jailbroken

[pruss]

1. Moreover, there is quite a bit you can do with adb even without root: the adb shell normally gets privileges that are higher than those ordinary non-system Android apps get, though lower than full root privileges. (E.g., you can silently install and deinstall arbitrary apps from an adb shell.) So keeping debug on and plugging into untrusted devices is probably not such a great idea, whether the device is rooted or not. Moreover, if debug is on, then even if the device isn't rooted, an attacker can often just silently install an app that roots the device via whatever vulnerability roots a given device, and then get full root privileges.

2. The Superuser app that I use can be set so that it remembers su permissions after the first time one is asked and doesn't ask again if the same app requests the permission (technically, it will ask again if the app requests the permission in connection with another su command, but most root-using apps just request permission for an su shell, and then do their work in the shell). I keep that setting active, since I do things that require root so often (my SuperDim app to dim the display below what the OS normally allows for use at night; on boot setting the exec permission on my SD card so I can move app libraries to it; adjusting CPU governor settings; using my Force2SD app to move recalcitrant apps to SD; running a script to do a tar backup of all of /data; etc.). It would be a real nuisance to be constantly prompted. But there is an obvious security cost to the convenience. I am willing to accept that cost, especially since I currently use only two root-based apps that I didn't write myself, and I think they are trustworthy apps. So only two apps that I didn't write have the silent su authorization enabled.

Re:Duh

[Miamicanes]

What you need is a USB CondomCable with the D+ and D- pins shorted together. No data can flow, and if the bad guys didn't bother to try and implement proper power protocol, you'll get the added satisfaction of frying THEIR hardware when your phone cranks up the juice and tries to suck down 1.7A instead of politely sipping 100mA. Just don't ever use such a cable by mistake to connect your phone to a pc or laptop belonging to yourself or a friend.

Re:Duh

[Kookus]

I don't think he meant that the d+/- lines were what fries the host, he was indicating that the phone wouldn't think it's connected to a computer and it would draw higher amps because it thinks it's hooked up to just a charger. So if the host didn't limit amps and it's wires weren't rated for 1.7A, then it would result in them overheating and hopefully damaging something.
The whole purpose was to make a connector that actually works, not something to destroy the host. The ancillary prize was damaging hosts if they were advertised as just a charger and they really weren't.