General > General Technical Chat
Hackers Can Now Trick USB Chargers To Destroy Your Devices
Halcyon:
--- Quote from: blueskull on July 22, 2020, 06:30:53 am ---
--- Quote from: Halcyon on July 22, 2020, 06:27:18 am ---I'd hardly call the voltages pumped into the Samsung Galaxy Note series as "instant". It was fairly continuous and the phone didn't even lock up or reboot. And we're talking about 215 volts, not 20.
--- End quote ---
USB killer is pulsed internally. It has a charger circuit from VBus, a capacitor, and a discharging circuit dumping charged voltage to D+/D- lines.
--- End quote ---
Even worse. Why would manufacturers bother only protecting the data lines and not bothering with the power as well? Phones routinely get charged off all kinds of shitty power supplies, everything from your crappiest Chinese adapters that are mains referenced, to noisy vehicle power adapters.
tom66:
--- Quote from: blueskull on July 22, 2020, 06:21:07 am ---Those phones handle an instant over voltage by absorbing it. There is a maximum energy limit and a maximum average power limit.
This PD/QC hack dumps continuous, current unlimited 20V to the phone, and no ESD diodes can take that.
--- End quote ---
No, but most modern phones have something along these lines:
https://www.maximintegrated.com/en/products/power/protection-control/protection-ics/MAX4987AE.html
This is the device that was fitted to my Samsung S4, and it provides OVP up to 28V even though the phone only supported 5V.
ESD diodes can keep the device within its momentary OVP limits as well.
Halcyon:
--- Quote from: blueskull on July 22, 2020, 06:44:58 am ---
--- Quote from: Halcyon on July 22, 2020, 06:35:32 am ---Even worse. Why would manufacturers bother only protecting the data lines and not bothering with the power as well?
--- End quote ---
You are not an EE at all, are you.
--- End quote ---
Nope, but I know the stupid shit that consumers do and what manufacturers are up against. You pay a premium for decent hardware for a reason (other than the badge).
--- Quote from: blueskull on July 22, 2020, 06:44:58 am ---
--- Quote from: Halcyon on July 22, 2020, 06:35:32 am ---Phones routinely get charged off all kinds of shitty power supplies, everything from your crappiest Chinese adapters that are mains referenced, to noisy vehicle power adapters.
--- End quote ---
I've yet to see a phone charger that is mains referenced. Metal phone chassis is almost always connected to DC- for RF performance reasons, using a mains referenced charger means reliable instant kill.
Noisy does not mean high voltage. 5V with 500mV noise is considered f*ing noisy, but 5.5V is not dangerous to electronics. A steady 10V can easily fry a phone regardless how clean it is.
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Watch Big Clive, he does several videos on "death-dapters".
tom66:
--- Quote from: blueskull on July 22, 2020, 08:16:39 am ---Just to put into perspective, people are desperate enough not to put DC/DC charger on board to save heat generation. Instead, they use a capacitive voltage halver and current doubler and rely on the external charger to define charging current and voltage.
When it comes to leading edge consumer electronics playing the war of number, things get totally crazy very quickly.
--- End quote ---
Do you have a link to this technology? I'm quite interested to understand this. Surely the phone must still support 5V USB charging to be compatible with existing kit, but the high power path is also available with compatible chargers.
Halcyon:
--- Quote from: blueskull on July 22, 2020, 08:31:17 am ---
--- Quote from: Halcyon on July 22, 2020, 08:24:23 am ---Watch Big Clive, he does several videos on "death-dapters".
--- End quote ---
He had featured a few mains referenced devices, none were intended to charge a phone.
--- End quote ---
From memory he did one on a camping light with a "5 volt" USB output which can be used for any consumer devices. He also did one on some coloured Poundland chargers which he ended up blowing up (on purpose).
The point is, dodgy USB adapters exist in the consumer market. I don't recall a single brand-name phone blowing up or having their port destroyed because of it. Many are designed (within reason) to cop what owners throw at them.
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