Is it safe to use public USB charging stations?

Question

I'm beginning to see more and more public device charging stations — okay, they're still mostly in airports — that include USB outlets, not just regular power outlets. Are these safe to use? Could someone with time, access and expertise rig one up so that it silently snoops in a connected phone's memory or loads a virus during charging?

To clarify, I know my phone usually asks me what to do if I connect it to something that tries to transfer more than just power, with a dialog box. I'm mostly concerned that there's a way for programs to unilaterally start doing things without a

Do you want to allow program BlahBlah to access your...

confirmation first.

This is known as [Juice Jacking](http://security.stackexchange.com/search?q=juice+jacking) — makerofthings7, Mar 14 '13 at 04:22
Also see this [Krebs article](http://krebsonsecurity.com/2011/08/beware-of-juice-jacking/) that explains the risks for a layman — makerofthings7, Mar 14 '13 at 04:23
I should've known there'd be a term for this already. Thanks, @makerofthings7 et al. — Pops, Mar 15 '13 at 12:53

score 3 · Answer 1 · answered Mar 14 '13 at 08:22

3

Depends on the phone. If you've disabled USB debugging/file sharing¹, then Android phones are inaccessible via USB until you turn it on.

On the other hand, one can access most files of an iPhone without any special access (this bypasses the pincode lock as well). Desktop applications like IExplore do this. While ssh access won't be available, they still can delete/steal your data, including applications, music, photos, and videos. As well as the configuration of applications (which may include passwords). And they can add their own malware.

^{1 These two are different. Most phones have debugging enabled by default, though you can turn it off. USB sharing is disabled by default, since it requires the SD card to be unmounted (which kills half your apps).}

answered Mar 14 '13 at 08:22

Manishearth

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*"one can access most files of an iPhone without any special access"* Did this change in iOS 7? – Pieter Oct 31 '13 at 20:17
@Pieter I doubt it. Not sure, though. – Manishearth Oct 31 '13 at 20:18
I'm asking because they introduced some anti-theft measures: http://support.apple.com/kb/HT5818 – Pieter Oct 31 '13 at 20:24
@Pieter doesn't mention anything about accessing the device, and seems to be something that kicks in if the phone is locked via Find My iPhone. Won't change the USB part. The USB part has to work for iTunes to work, though they could in theory make a whole bunch of changes to everything to make it secure. Doesn't look like they have. – Manishearth Oct 31 '13 at 20:29

Is it safe to use public USB charging stations?

1 Answers1