Do computer monitors have security holes?

I’m looking to get a monitor and I was wondering if any monitor will do regarding security and privacy concern. Sorry if my question sounds amateurish, I am totally amateur! But I wonder if the usual monitors have some kind of backdoor, or if some communicate with their original company without being able to do anything about it. Also, I’m waiting for suggestions for any particular brand of monitor you might be experience with. There is a good chance I will get a Happy Hacking Keyboard, so you can see the style I am looking for. Simple, efficient. I will only be using linux operating systems. Thanks to all, and I can’t wait for the librem 14 to be available.

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I haven’t heard of monitors having back doors. They would need network access, some way to communicate back.

A smart tv can double as a monitor. They often request network access, and have Netflix, Roku, other stuff built in. Those tv’s will also request something like “Can we watch your screen to see what you like so we can make recommendations?” Which to me sounds like a horrible idea :slight_smile:

Anyways, I’ve never heard of a computer monitor having a backdoor, but I wouldn’t recommend hooking up the computer to a smart tv.


What @leetaur said about a smart TV. There are also smart TVs that have security holes (that may not be backdoors i.e. genuine bugs). Although it may be safe enough if the smart TV is not connected to the network - which is easiest to guarantee if the smart TV is ethernet only (no WiFi).

However there

  • are exploits involving remote sensing of what is on the screen (serious adversary threat model)
  • is an ethernet channel in HDMI 1.4 and later
  • are monitors with built-in USB hubs that open up the potential for additional exploits
  • and as a special case of the previous, any monitor that is provided with video via USB-C in DisplayPort (or other video) AltMode by definition opens up USB for potential additional exploits.

The more feature rich the monitor, the more likely to have security holes (more places for backdoors to hide, more places for humans to stuff up).

The monitor would not be the part of the computer system that most worries me.


And here I thought the biggest security hole a monitor had is that anyone looking at it can see what’s on the screen.


This is a pretty impressive demonstration:


In that case I’ll be choosing a 27 micron monitor.

Makes me never want to own a smart tv!

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well, I guess if someone powerful enough decide to spy on what is on my screen, I’m screwed. Pretty impressive indeed. Do you imagine this kind of cannon floating around earth and spying on monitor screen?

If you are so paranoid then you better not write public indications that you have something to hide.

Lesson 1: don’t do it.
lesson 2: tell nobody.


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And there are also the folks that can decrypt what is on your screen just by the reflected flicker on your walls. But you either have to be really paranoid or a target to worry about it.

Crazy. ^^ The manifold world of side channel attacks. Do you have a link about that?

dangit guys. sometimes i feel you’re here just to mix credible bluffs with facts … for national security ofc … :joy: :innocent: :smiling_face_with_three_hearts:

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I think the hack is old stuff not news. I’d have to use google a to find a historical article on it.

Go for it!

Like I said, this is old stuff, I don’t know if decades later digital displays are better “filtered” (per earlier chapters). So starting with Chapter 6 page 105. Didn’t have to use google however, DDG found it. But yes, normally CRT eavesdropping is a TEMPEST problem. But the visual spectrum is often ignored.

Excerpt page 106:

So even if an observer can pick up only the average luminosity ofa CRT surface, for example, by observing with a telescope the diffuse light reflected from nearby walls, furniture or similar objects, a low-pass filtered version of the video signal becomes accessible. Not even curtains, blinds or windows with etched or frosted glass surfaces – as are frequently used to block views into rooms – are necessarily an effective protection, as the average luminosity inside a room can still leak out.

Addendum: user1 will freak after reading this.

More addedum: LCDs and LEDs are discussed in later pages.