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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

#642

As an alternative to a camera cover, use the camera indicator light to determine if your camera is active I've been thinking about privacy all wrong. I thought it was about preventing access to my data... but Apple has cleared up my misunderstanding and now I know that it's just about being notified when my data is stolen. Everyone feel free to post your credit card numbers... your privacy is secure, since your bank…

[deleted]

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

#643
post #554

Earlier quoted context omitted.

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.

So... ?

Problem is people dont trust software. People want a hardwired fix.

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

#644

Earlier quoted context omitted.

No, the point is that old light indicators were done in software (and were open to exploits), whereas newer indicators have all since moved to being wired right in the hardware. The power of the webcam lights up the indicator.

But most of this 'hardware' is still software. Firmware inside the webcam itself, which could also be hacked. Most webcams do report themselves to the OS while inactive, so they are actually communicating with the system (and thus powered)

If the sensor is physically getting power, the light is too, unless the wire is broken. They are on the same circuit. It is not a firmware thing, its basics circuits Physics 101. The light could be burnt out, yes. The wire could break sure. But it can't be hacked (minus pulse modulation, not giving the light enough time to light up). But if you power up the camera, and something isn't physically broke... the light comes on. I know the privacy incident has already happened, separate argument. I think people are missing the hardwired point. This discussion should be focusing on the fact that if the camera has powered on, and we see it, it's already too late.

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

#645

Earlier quoted context omitted.

Actually it would be a huge security risk if everyone posted their CC numbers publicly. Attackers could use their numbers to make purchases, and by the time the purchases show up on the statement the money is already gone.

Banks don’t transfer money to CC merchants immediately - it happens later after the hold period is passed. Also transaction can be reversed via chargeback.

Is it not clear that they're not complaining about the literal situation of credit card breach, but rather using it as analogy to being informed of a breach after the fact?

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

#646

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.

The Pinebook Pro uses a key combination, managed by the keyboard firmware. That's not quite as good as a hardware switch, but it shrinks the attack surface considerably.

This is the way to do it.

I always used to say I don’t cover the webcam on my MacBook Pro because any hack sufficient to activate it without my knowledge would mean the attacker already has root, including my bank login, etc, and I’d just be closing the barn door after the horses have left.

In the Covid era, however, my threat model is no longer unlikely malicious actors with root , but more plausible bugs in my conference software. I’m not worried that a statistically implausible attacker has a zero-day on my webcam, but that Zoom has a bug that will default the camera to on despite my settings as I join standup coming out of the shower. If there were a firmware-based gesture to explicitly turn the camera on, I wouldn’t need the tape.

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

#647
post #612

Earlier quoted context omitted.

The “versions of MacBook laptops and iMac desktops” they are referring to are the ones from more that 8 years ago that didn’t have the hard wired LED. Nowadays there is literally a wire from the sensor to the LED. If the sensor is on, the LED is on. It’s got nothing to do with firmware.

What happens to the connection if the LED burns out? Is the LED lifetime sensitive to state change such that you could flicker it via rapid camera toggling to burn duty cycle overnight? If someone had access briefly to your laptop at a coffee shop, could they cover the LED with black opaque cellophane? This sort of attack is pretty specific, so you figure it’s only done by people who want something from you in partic…

LEDs don't burn out in regular usage conditions

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

#648
This statement has a number of issues.

First, you have to trust Apple that the indicator _really_ can't be disabled. You also have to trust that there isn't a vulnerability Apple is not aware about that could allow rolling the camera without the light coming on. This has happened in the past [0] and there are known Apple products that are vulnerable, yet the statement never mentions this making you believe it's impossible.

Second, once the camera light is on, the data has already been captured. The light just told you about it, not prevented it. The plastic cover or a piece of tape does prevent it even if your laptop security is compromised.

Third, in a world where remote conferences are more and more common, more and more software doesn't do a very good job at letting you know when it's about to enable your camera. You might click on a link to an all hands conference to listen in while you're changing only to have the software helpfully enable the camera and broadcast you for the rest of the company. I believe in big conferences organizer may sometimes control other ppl's camera as well. You can totally imagine a scenario when the organizer misclicks and enables the camera for the wrong person instead of a scheduled presenter.

Camera covers solve all of those problems.

[0]: https://jscholarship.library.jhu.edu/handle/1774.2/36569

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

#649
post #629

Earlier quoted context omitted.

How do you know? And how do you know there is not a bug in the electrical design?

The circuitry can't be that complex. Meaning the likelihood of a bug being pretty low. I mean come on, it's a wire attached to the camera power source with a resistor and a LED.

How do you know? How do you know how the LED is implemented?

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

#650
post #125

Here’s the document explaining how it’s physically impossible to use the microphone when the MacBook lid is closed: https://support.apple.com/en-gb/guide/security/secbbd20b00b/... Where is the equivalent document explaining how it’s physically impossible for the camera to be active without the green LED lighting up?

They also claim that if you add a (MFI-compliant) case to the iPad, and close it, that this similarly disconnects the microphone. The simplest mechanism to do this sounds complicated enough that it reduces my confidence in the mechanism. The point of half the comments in this thread is that a hardware interlock mechanism needs to be dead simple. This sounds like a step in the wrong direction.
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