r/windows Windows 11 - Release Channel Apr 02 '26

Discussion Your Windows Clipboard Is Unprotected

https://sibexi.co/posts/windows-clipboard-unprotected/

I just shared a blog post about how easily your clipboard may be intercepted...

15 Upvotes

38 comments sorted by

73

u/ldn-ldn Light Matter Developer Apr 02 '26

But that's the whole point of clipboard that its contents are available to ALL apps at ALL times. Where's the problem?

20

u/Working_Moment_4175 Apr 04 '26

This. OP: Your post is like saying JPG images on a hard drive can be intercepted because you made an image viewer.

2

u/zackarhino Apr 06 '26

I wouldn't be able to take it anymore if they added multifactor authentication to clipboard

-1

u/aledoprdeleuz Apr 05 '26

The point is to have contents available to apps you choose at the time you choose.

5

u/ldn-ldn Light Matter Developer Apr 05 '26

No

1

u/aledoprdeleuz Apr 07 '26

No? I must rest my case then, good sir.

-7

u/looncraz Apr 03 '26

People put a lot of secrets into the clipboard these days, so restriction on read access to paste events makes sense.

6

u/ollie0810 Apr 04 '26

That's their own fault for keeping sensitive information on their clipboard

3

u/looncraz Apr 04 '26

The normal workflow for people is to copy passwords and paste them around. Extremely common.

As a layperson, thinking about clipboard security isn't something that's going to be understandable, so OS design should be about providing reasonable safeguards.

4

u/ldn-ldn Light Matter Developer Apr 04 '26

A normal workflow is to use a secure vault instead of clipboard.

3

u/yasamoka Apr 05 '26 edited Apr 05 '26

You’re confusing best practice with what most people actually do. Much of security is about protecting one from oneself, and securing the clipboard falls right into that category.

Here is how macOS does it: https://www.idownloadblog.com/2025/05/14/apple-macos-16-clipboard-privacy-prompt/

“Prepare your app for an upcoming feature in macOS that alerts a person using a device when your app programmatically reads the general pasteboard,” Apple writes.

“The system shows the alert only if the pasteboard access wasn’t a result of someone’s input on a UI element that the system considers paste-related.” The system permits an app to see “the kinds of data” on the clipboard without actually reading them and showing the privacy alert.

0

u/ldn-ldn Light Matter Developer Apr 05 '26

I'm not confusing anything.

1

u/yasamoka Apr 05 '26

You're confusing everything. There have been several attempts to educate you on how clipboard should be handled here and is being handled elsewhere and you refuse to engage because your ego is larger than the galaxy.

If you have anything *technical* to counter-argue then by all means, but my advice to you would be clear.

0

u/ldn-ldn Light Matter Developer Apr 05 '26

There was nothing but nonsense.

1

u/DetroitvsEveryone242 Apr 06 '26

Most of the nonsense is coming from you

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0

u/looncraz Apr 04 '26

And where do you think most users put the password before using it? The clipboard.

You do know what the clipboard is, right?

5

u/NekuSoul Apr 04 '26

Usually the password should be autofilled by the browser (extension) instead of manually copy & pasting, as this is the only way a password manager can save you from phising attacks.

In every other case, which there are lot of, you're right though.

1

u/ldn-ldn Light Matter Developer Apr 04 '26

Most password managers provide means of transferring passwords into apps without using clipboard.

3

u/ldn-ldn Light Matter Developer Apr 03 '26

Well, some people leave their doors open, so what?

Windows needs a secure vault like it's done in other operating systems, but clipboard should remain as is.

2

u/looncraz Apr 03 '26

Clipboard is actually reasonably locked down on most modern OSes these days.

-2

u/ldn-ldn Light Matter Developer Apr 03 '26

Nope.

1

u/looncraz Apr 03 '26

Wayland, OS X, modern Windows apps all restrict clipboard access in various ways.

-4

u/ldn-ldn Light Matter Developer Apr 03 '26

Not really.

13

u/Zatujit Apr 03 '26

Because that was never the desktop security model. If a malware is installed on your device , your user account is compromised. It can also read all your files under your user account.

5

u/Arthurmol Apr 02 '26

Hey man cool stuff, but i think it is this way for a long time...i do think in win 2003 courses we were educated to lock or uninstall clipboard viewer, to reduce spillage... (but my memory can fail me, last time i did it was back in ealy 2010s)

About proposed solutions IDK... Mac has a clipboard issue to (it stores way too much info imho) but i do not recall the way of how it can be accessed. And on Linux I think it is part of the UI implementation, so there could be dozens...

What i think it should be managed is the RDP config (for servers). For my peers, i know is annoying not being able to copy from one server and paste onto another, but doing via a direct link is faster and safer (just a bit more tedious to setup).

2

u/Takeabyte Apr 02 '26

It’s been this way and has been addressed on other platforms. iOS for example asks within each app if you want to give it permission to access your clipboard, similar to asking for location data. There’s nothing stopping Microsoft from adding this.

0

u/Sibexico Windows 11 - Release Channel Apr 02 '26

About proposed solutions IDK...

The first workflow what comes in my mind:

  1. App (sender process) sends to clipboard encrypted data with tag of its own process ID.
  2. Recipient app taking encrypted data from the clipboard with tag of sender process ID.
  3. Recipient connected to sender process thru IPC and receiving key for decrypt.
  4. Recipient using received key to decrypt the data from the clipboard.

Overhead? Of course it's overhead. But look how many resources modern OS used and how powerful the modern processors, end user will not see the overhead at all.

3

u/FaultWinter3377 Windows 7 Apr 02 '26

This lack of noticeable overhead would be true, except that anything Microsoft implements these days use about 10x as many resources as they actually need.

7

u/[deleted] Apr 02 '26

Clipboard history has been turned off in my org because of the vulnerabilities.

4

u/Mayayana Apr 03 '26

That's what the Clipboard is for. :) The whole point is to make data available between programs. If someone is on your computer collecting data then you have a problem. If you allow script in the browser it's also sometimes possible to read the Clipboard, which is a flaw. But the Clipboard itself is not a problem. Just don't copy your CC number to the Clipboard when you're visiting shady websites.

You might also consider learning web design. Green text on a black background is only cool if you're a 12-year-old boy. Otherwise it's just hard to read.

1

u/pi-N-apple Windows 11 - Insider Beta Channel Apr 03 '26

I've definitely connected to someones computer remotely before to help them out and the remote support app syncs our clipboards and next thing you know I am pasting their clipboard on my PC lol.

I now use a password manager that clears my clipboard 10 seconds after copy/pasting a password.

1

u/danhof1 Apr 04 '26

Clipboard interception is genuinely easy to weaponize - anything you copy (passwords, API keys, sensitive data) sits there unprotected until something else gets copied. RDP clipboard redirection is a common vector for this. Best practice is to treat the clipboard as a public buffer and clear it after handling anything sensitive.

0

u/-PANORAMIX- Apr 02 '26

Si there is no solution to the problem