In earlier versions of Windows 10, a security bug allowed to access the clipboard from the lock screen. This issue was fixed in the Windows 10 1803 and newer versions.
In this post, I’ll explore this security issue and how clipboard data was exposed.
Clipboard Access in Lock Screen
Accessing the clipboard from the lock screen in Windows 10 is generally not possible due to security constraints. The lock screen is designed to restrict unauthorized access to your system, and that includes clipboard data.
Clipboard data can contain sensitive information, and allowing access to it from the lock screen would pose a security risk.
However, if you’re an administrator and you have a specific use-case that requires such functionality, you might be able to create a workaround using custom scripts or third-party software, but these methods would likely require you to bypass or weaken existing security measures, which is not recommended.
It’s crucial to understand the security implications of making such changes. Modifying system behavior to access the clipboard from the lock screen could expose your system to various security vulnerabilities.
Therefore, I strongly recommend considering alternative solutions that do not compromise system security.
Security Issues on Windows 10 Lock Screen
Unlike earlier versions of Windows, the Windows 10 lock screen no longer runs on the winlogon secure desktop. Instead, it runs on the default (normal) desktop, but you can’t switch apps, bring other windows to the foreground, etc.
Unfortunately, this doesn’t stop users from exploring other apps with the review cursor, reading/manipulating the clipboard, messing with the user’s NVDA configuration, etc. IMO, this is a pretty nasty security issue in Windows itself, but this is apparently what Microsoft have chosen to do.
We can’t simply start a secure copy of NVDA, as that would involve restarting the user’s normal copy (since this is on the default desktop), which would result in loss of state and potentially be a bit slow. Therefore, we’re going to have to somehow disable relevant parts of NVDA.
I think this will basically consist of three parts:
- Preventing the user from object navigating out of the lock screen;
- Blocking all non-essential scripts;
- If we want to allow the synth settings ring commands, creating a temporary configuration which is thrown away when the lock screen goes away.
Expose Locked Windows 10 Clipboard Data
The clipboard cannot be accessed from the lock screen in Windows 10, unlike in earlier versions of Windows 10 where this was possible owing to a security flaw.
You can run scripts or look for other ways to get around this, but I don’t think it’s a good idea to allow the clipboard on the lock screen because it could be dangerous for your security.