MacBook – Does a modern MacBook’s green “camera light” always turn on when the camera is activated

cameramacmacbook prowebcam

Many people are seen to put strips of tape and other adhesive materials on their MacBook camera in an attempt to thwart any potential hacker from accessing their system and camera. MacBooks have a green "camera light" on the right side of the FaceTime camera on the front that seems to turn on when the camera is activated (i.e. the sensor is provided energy and transmits a signal to the motherboard).

Does the camera of a modern MacBook require that the green camera light turns on as well? In other words, is the camera light hardwired to the camera in such a way that if the camera is supplied electricity, that itself would enable the camera light? This would prevent a hacker from being able to obtain any information from the camera without the user being notified by the green light.

I've seen this question come up again and again, but no satisfactory/definitive answers were provided. The last time such a question was posted received an answer that linked to a research paper showing that it is possible to activate the camera without activating the camera light—but only on pre-2008 Macs. The answers to another question question come to a similar conclusion. A user did say that there was "[no] proof that you can do the same in post-2008 laptops," but this doesn't prove that the camera light is in fact hard-wired to the camera.

The fact that there is no proof for such an important security feature is rather strange. There must have been a group of designers and engineers who created the camera system—surely they would know and would have publicized this perhaps in an Apple support article or in an interview? Or perhaps this could have been discovered in a teardown by a group at iFixit (although I am no electrical engineer), but this doesn't seem to have happened yet. Most importantly, I would expect Apple to tout this as a security feature, but there is no mention of it on their site. Is there really 'no proof' as to whether the camera and camera light is hardwired or not?

Best Answer

There must have been a group of designers and engineers who created the camera and camera light system – they would surely know and have told others.

John Gruber received an email from one such former Apple engineer:

https://daringfireball.net/2019/02/on_covering_webcams

Security researchers at Johns Hopkins released a paper in 2013 revealing that the indicator lights on Macs released prior to 2008 could be circumvented by software. I linked to this in 2016, wondering if the same exploit was possible on more recent Macs. Here’s an answer I received from a former engineer at Apple who was intimately familiar with the software drivers for Mac webcams:

The original cameras had the problem that the JHU researchers detailed in the article that your linked to. Problem was that the firmware was downloaded on every boot and there was no security/encryption mechanism for verifying it. The part used was fairly common and the firmware was just in RAM (hence the loading after a cold boot), as oppose to flashed.

All cameras after that one were different: The hardware team tied the LED to a hardware signal from the sensor: If the (I believe) vertical sync was active, the LED would light up. There is NO firmware control to disable/enable the LED. The actual firmware is indeed flashable, but the part is not a generic part and there are mechanisms in place to verify the image being flashed. […]

So, no, I don’t believe that malware could be installed to enable the camera without lighting the LED. My concern would be a situation where a frame is captured so the LED is lit only for a very brief period of time.

The still photo problem — where the light only turns on for the instant the image is being captured — is interesting. But I would wager real money that the camera indicator light cannot be circumvented by software on any Mac released this decade.

emphasis mine

Related Question