8 ms·

On laptops, there's usually a light that turns on when the camera is active. I (like to) believe that this light is controlled by the camera's firmware, i.e., i

by zvrba 7y ago

On laptops, there's usually a light that turns on when the camera is active. I (like to) believe that this light is controlled by the camera's firmware, i.e., it can't be manipulated by software? Can someone knowledgable confirm this?

shakna 7y ago
> I (like to) believe that this light is controlled by the camera's firmware, i.e., it can't be manipulated by software? Hit and miss. If it can be controlled by the camera's firmware, then it can be controlled by software. All it takes is a bug in the firmware, which is unlikely to ever be updated. Some camera lights are controlled by the firmware, others are wired onto the data line, so the moment data is going either way, they light up. However, defeating the light even in the directly wired case is possible, and has been done many times. If you fire up the camera, take a photo, and turn off quickly enough, the light won't be perceived by the victim. (I believe the FBI and the NSA both had tools that did this that became public knowledge a number of years ago).
- gumby 7y ago
  > All it takes is a bug in the firmware, which is unlikely to ever be updated. FWIW, Apple system (OS) updates frequently include firmware updates, not only for the FEP/boot code but other devices as well, especially for security issues. Apple has been pretty good about this. Not addressing the rest of your comment, just this one point. PS: don’t know why the phones don’t have a similar indicator for “front camera on” and “speaker mode on”. BOM cost I suppose.
- lloda 7y ago
  The hardware could easily be designed so that whenever the light is turned on, it cannot be turned off for a second or w/e. Seems like an obvious solution.
  - moooo99 7y ago
    iirc some laptops do this. As soon as there is data transmitted from the camera, the light will turn on. Another solution would be the sliding camera cover some manufacturers have, but that doesn't really help with the built in microphone.
eknkc 7y ago
It is. However there was an exploit on older macbooks where an attacker managed to flash the firmware, disabling the led. I believe recent macs are much hardened on both hardware and software. Still a possibility.
Dobbs 7y ago
I was under the distinct understanding that on modern macbooks it was hardwired in. If the camera receives power, then the light is on. If the camera doesn't have power then the light is off. edit: seems I'm wrong from googling
simonh 7y ago
On modern Macs since some time before 2016 there is a hardwired line from the sensor to the LED that is not vulnerable to a firmware hack[0]. However, if an app just takes still photos the light could be on for a very brief period of time. [0]https://daringfireball.net/2019/02/on_covering_webcams https://daringfireball.net/2019/02/on_covering_webcams
- danieldk 7y ago
  Also, the Mic is disconnected in hardware when you close the lid: https://support.apple.com/guide/security/hardware-microphone-disconnect-mac-ipad-secbbd20b00b/web https://support.apple.com/guide/security/hardware-microphone...
speedgoose 7y ago
The light isn't really a good solution anyway. "We observed that, on average, fewer than half of our participants (45%) noticed the existing indicator during computer-based tasks. When seated in front of the computer performing a paper-based task, only 5% noticed the indicator." - Somebody's Watching Me?: Assessing the Effectiveness of Webcam Indicator Lights - https://dl.acm.org/doi/abs/10.1145/2702123.2702164 https://dl.acm.org/doi/abs/10.1145/2702123.2702164
- WilTimSon 7y ago
  Could those stats be improved with a different type of light/higher intensity? A sound notification wouldn't be practical, I suppose, but that is also easier to notice than a tiny green dot on the top of the screen.
  - neilalexander 7y ago
    If the LED blinked for 5-10 seconds before turning steady then it might be more readily noticed.
    - reaperducer 7y ago
      Or, if on a phone, the flash could strobe for a certain amount of time.
ForHackernews 7y ago
Recent Thinkpads have a physical plastic cover that slides to obscure the camera.
oefrha 7y ago
In addition to the hardware light, I also use Micro Snitch (from the maker of Little Snitch) which provides on-screen notification whenever the camera/microphone is activated/active. https://obdev.at/products/microsnitch/index.html https://obdev.at/products/microsnitch/index.html
- Etheryte 7y ago
  Oversight (by Objective-See) is another great alternative, covers the same use-case with block and allow notifications. https://objective-see.com/products/oversight.html https://objective-see.com/products/oversight.html
- nathancahill 7y ago
  Clever name. Love both products.
deleted 7y ago
[deleted]

by zvrba 7y ago

shakna 7y ago

> I (like to) believe that this light is controlled by the camera's firmware, i.e., it can't be manipulated by software? Hit and miss. If it can be controlled by the camera's firmware, then it can be controlled by software. All it takes is a bug in the firmware, which is unlikely to ever be updated. Some camera lights are controlled by the firmware, others are wired onto the data line, so the moment data is going either way, they light up. However, defeating the light even in the directly wired case is possible, and has been done many times. If you fire up the camera, take a photo, and turn off quickly enough, the light won't be perceived by the victim. (I believe the FBI and the NSA both had tools that did this that became public knowledge a number of years ago).

gumby 7y ago
> All it takes is a bug in the firmware, which is unlikely to ever be updated. FWIW, Apple system (OS) updates frequently include firmware updates, not only for the FEP/boot code but other devices as well, especially for security issues. Apple has been pretty good about this. Not addressing the rest of your comment, just this one point. PS: don’t know why the phones don’t have a similar indicator for “front camera on” and “speaker mode on”. BOM cost I suppose.
lloda 7y ago
The hardware could easily be designed so that whenever the light is turned on, it cannot be turned off for a second or w/e. Seems like an obvious solution.
- moooo99 7y ago
  iirc some laptops do this. As soon as there is data transmitted from the camera, the light will turn on. Another solution would be the sliding camera cover some manufacturers have, but that doesn't really help with the built in microphone.

eknkc 7y ago

It is. However there was an exploit on older macbooks where an attacker managed to flash the firmware, disabling the led. I believe recent macs are much hardened on both hardware and software. Still a possibility.

Dobbs 7y ago

I was under the distinct understanding that on modern macbooks it was hardwired in. If the camera receives power, then the light is on. If the camera doesn't have power then the light is off. edit: seems I'm wrong from googling

simonh 7y ago

On modern Macs since some time before 2016 there is a hardwired line from the sensor to the LED that is not vulnerable to a firmware hack[0]. However, if an app just takes still photos the light could be on for a very brief period of time. [0]https://daringfireball.net/2019/02/on_covering_webcams https://daringfireball.net/2019/02/on_covering_webcams

danieldk 7y ago
Also, the Mic is disconnected in hardware when you close the lid: https://support.apple.com/guide/security/hardware-microphone-disconnect-mac-ipad-secbbd20b00b/web https://support.apple.com/guide/security/hardware-microphone...

speedgoose 7y ago

The light isn't really a good solution anyway. "We observed that, on average, fewer than half of our participants (45%) noticed the existing indicator during computer-based tasks. When seated in front of the computer performing a paper-based task, only 5% noticed the indicator." - Somebody's Watching Me?: Assessing the Effectiveness of Webcam Indicator Lights - https://dl.acm.org/doi/abs/10.1145/2702123.2702164 https://dl.acm.org/doi/abs/10.1145/2702123.2702164

WilTimSon 7y ago
Could those stats be improved with a different type of light/higher intensity? A sound notification wouldn't be practical, I suppose, but that is also easier to notice than a tiny green dot on the top of the screen.
- neilalexander 7y ago
  If the LED blinked for 5-10 seconds before turning steady then it might be more readily noticed.
  - reaperducer 7y ago
    Or, if on a phone, the flash could strobe for a certain amount of time.

ForHackernews 7y ago

Recent Thinkpads have a physical plastic cover that slides to obscure the camera.

oefrha 7y ago

In addition to the hardware light, I also use Micro Snitch (from the maker of Little Snitch) which provides on-screen notification whenever the camera/microphone is activated/active. https://obdev.at/products/microsnitch/index.html https://obdev.at/products/microsnitch/index.html

Etheryte 7y ago
Oversight (by Objective-See) is another great alternative, covers the same use-case with block and allow notifications. https://objective-see.com/products/oversight.html https://objective-see.com/products/oversight.html
nathancahill 7y ago
Clever name. Love both products.

deleted 7y ago

[deleted]