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Don't close your MacBook with a cover over the camera

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Re: Don't close your MacBook with a cover over the camera

#551
post #169

Earlier quoted context omitted.

The question is whether this is a firmware implementation that's just waiting for a 0-day or if the +V for the CMOS sensor is literally wired to the LED. If the latter I'd like to see a picture of it.

Hi! I was the security architect for this feature on recent Macs. The LED is wired to the camera PMIC and is powered by the voltage rail that powers the camera. The PMIC will always remain on if the system has power. Macs newer than 4 or so years also have a feature that forces the LED to stay lit for at least 3 seconds after it has been turned on to prevent the single-frame-grab attack.

Out of curiosity...

Do the doors at Apple HQ have locks? Or is there just a little LED next to them that lights up when they open?

Re: Don't close your MacBook with a cover over the camera

#552
post #379

Earlier quoted context omitted.

People forget because you have to train yourself to remember, and outside of intelligence agency personnel, no one is doing that. Camera covers are just another example of security for show. Having a camera cover on a pc without a hard wired camera indicator like Macs have means you will never know how many of those times you were filmed after forgetting to slide your camera cover over.

I don't think anyone suggested removing the LED camera indicator if a camera cover is added. They serve different functions, even though there is an intersection. The camera LED indicates whether the camera is powered on or off, when the LED functions correctly. The cover guarantees that the camera cannot capture video when closed.

The LED is an instant indicator of being hacked, well before they can collect anything embarrassing. Unless you are a 24/7 nudist with a privacy fetish.

Re: Don't close your MacBook with a cover over the camera

#553

Earlier quoted context omitted.

And the hackers still win, cause no one remembers to slide it shut after a call, and they can hack the led so there is no physical indicator when they are watching.

I honestly can't remember the last time I used my camera during a company meeting, and I've been working remotely since March. So, there's definitely value to a built-in cover; in my case it would stay shut permanently.

A piece of tape does that without the security theatre of a cover.

Re: Don't close your MacBook with a cover over the camera

#554

Earlier quoted context omitted.

If Apple makes such high-end stuff, and is marketing on privacy, why can't they spring for hardware switches? Pine64 does, and they're by no means high-end. Not by price, anyway.

I don't think the price of a hardware switch would be a concern for Apple, but the size would. A hardware switch would take up space. Apple broke their keyboards to shave a couple millimeters of thickness off their laptops.

You still have a silent mode toggle on your iphone. I think apple can figure out how to add a hardware switch for a camera/mic to a laptop without compromising thickness.

It doesnt need to be a hardware cover, just a hardware killswitch to the circuit.

Re: Don't close your MacBook with a cover over the camera

#555

Earlier quoted context omitted.

There's a reason Zukerberg's laptop has its mic and camera tapped up. It doesn't matter what device you use unless there's a physical switch to disconnect it'll never be safe. Software can ALWAYS have zero days, just because it hasn't been exploited yet doesn't mean it can't be.

But can't you specifically wire the indicator light to always be lit if the camera has power? I don't see Apple claiming they've done that but a correct design would make the indicator light work that way and be related to software at all. Meaning you could only disable the indicator light by physically modifying the device.

A couple hypotheticals here:

A way to overvoltage/current and burn out the LED. Probability low, but nonzero.

More plausible situation: There are times when the camera is pointed at me, but my head is not pointed at the camera. Perhaps I left the laptop on in the corner of a room while it's playing music, or a myriad of other things.

A cover is a simple, foolproof solution to the camera issue.

Re: Don't close your MacBook with a cover over the camera

#556

None of the proposed solutions do anything to actually stop the camera from taking a picture of you. Sure, you'll see the indicator light up for 3 seconds. But the attacker still got what they needed. Camera covers have nothing to do with identifying compromise. They are strictly for preventing compromise. This is exactly opposite what a camera indicator light does, and thus the indicator should not be considered a "…

Exactly!

Apart from that, I would be absolutely amazed if there isn't at least one failure mode of the led itself that allows the camera to turn on despite no light being emitted. Probably too rare for most people to worry about, but still.

I really get why people want a cover, and I think Apple are being a bit disingenuous trying to convince people they don't need one. It's fine they warn about the danger of cracking the screen, but that entire "we protect your privacy spiel" was rather terrible, and also quite misleading as you so clearly pointed out!

Re: Don't close your MacBook with a cover over the camera

#557
post #554

Earlier quoted context omitted.

I don't think the price of a hardware switch would be a concern for Apple, but the size would. A hardware switch would take up space. Apple broke their keyboards to shave a couple millimeters of thickness off their laptops.

You still have a silent mode toggle on your iphone. I think apple can figure out how to add a hardware switch for a camera/mic to a laptop without compromising thickness. It doesnt need to be a hardware cover, just a hardware killswitch to the circuit.

> You still have a silent mode toggle on your iphone.

Yes, and it's one of, what, three moving parts left? Even the home button on the iPhone 7, 8, and 2020 SE is fake, it doesn't actually depress.

Re: Don't close your MacBook with a cover over the camera

#559
post #514

Earlier quoted context omitted.

Indeed, I'm a little surprised Apple didn't follow the Thinkpad approach of simply having a sliding piece with an aperture that extremely obviously blocks the camera. Surely Apple can't seriously think their users would be confused by this and complain... I don't think my desktop computer's webcam is likely to get hacked either but I'm still going to unplug it when I'm not using it. Complex systems are hard to secure…

The original iSight camera had a leaf shutter. It's not a foreign concept to them.

The original iSight had a hundred times more depth and also happened to be an external camera. Bringing it up here is irrelevant.

Re: Don't close your MacBook with a cover over the camera

#560

Earlier quoted context omitted.

I think newer ones even route it through the T1 chip. Need to look again. There was an exploit, over 10 years ago like you said, that allow to disable it. But that was corrected. Edit - iıSeeYou: Disabling the MacBook Webcam Indicator LED - This was 2008 - https://jscholarship.library.jhu.edu/bitstream/handle/1774.2... Looking for t1 links. Edit 2 Can't find anything confirming the t1 right now..

The T chip in modern MacBooks is the T2, and it's certainly used for the mic cutoff. I'm unaware of public disclosures around it's use for the camera. https://support.apple.com/guide/security/hardware-microphone...

On MacBooks the disconnect is done without the T2 being involved.
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