Ask HN: iPad says USB accessory detected when plugging into power | Hacker News Reader

Ask HN: iPad says USB accessory detected when plugging into power

5 pointshereforphone14 comments

I bought a power strip with USB outlets. This is a no-name brand likely from China. When I plug in my iPad, I got the message above. Is there something shady going on?

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It's a warning that it's not an Apple-approved device

It may (or may not) be "shady"

It's an especially helpful message when plugging into a not-before-seen computer

It's also helpful as a warning that you may not have as high a QC standard for the charging device as you should for your $1000 pocket supercomputer we call a smartphone

Why would it be a device at all? It's supposed to be a charging outlet.

Because it's not merely a "charging outlet" ... there's electronics in the charger to convert AC to USB power out :)

As I understand it these typically just use the power rails of the USB interface. I've used several AC->USB converters in the past, and they haven't been detected as a device. This is unusual at least in my experience.

I've yet to see a charger I've bought anywhere not give the warning the first time I plug into it

Happens pretty frequently with cables, too

Proper USB power supplies have the USB data pins shorted out, or a special resistor divider configuration to signal power delivey capabilities for Apple devices. No actual USB data communication. I would be very curious what is going on, are you willing to take apart the power supply?

Maybe a smart-ish charger that can identify Samsung or other tablet for fast charging and iPad see the foreign crosstalk as a potential controller.

Also could be a way to encourage sales of apple authorized chargers...

There could be something shady going on but I've seen this message occasionally with my OEM cable. Realistically, what could a secret device in your cable do?

Couldn't it be a keyboard that delivered a set of keystrokes to retrieve malware by opening a web browser or some other common program?

Act as a keyboard ("rubber ducky"), retrieve pictures if allowed, exploit some zero day, ...

Can you take it apart? Even if it was spying, how could it connect to Wi-Fi. Also how could the OEM connect to it?

There are ways, like a cellular modem or LoRaWAN

Did you buy it from Amazon by any chance?

I bought it from Amazon in a country that's not the US

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