A researcher has discovered that Windows 11 exposes the same flaw as the Google Pixel: images taken with the Snipping Tool can be “recomposed”, even if you have modified them.
Two researchers had exposed a flaw in the Google Pixel screenshot editing tool that allows malicious people to undo changes made to an image and extract sensitive information from it. A cybersecurity expert named Christian Blume discovered that the Windows 11 Snipping tool is affected by the same problem. He was obviously quick to share his discovery on Twitter.
I’ve got a fun one for you all to look at.
I opened a 198 byte PNG with Microsoft’s Snipping Tool, chose “Save As” to overwrite a different PNG file (no editing), and saves a 4,762 byte file with all that extra after the PNG IEND chunk.
Sounds similar 😀
—Chris Blume (@ProgramMax) March 21, 2023
If you’re used to posting edited photos through the Windows 10 or Windows 11 Snipping tool, it might be best to hold off until a patch is made to Windows. Indeed, an ill-intentioned Internet user could try to cancel the modifications that you have made, even if only partially, and recover possibly confidential information from the snapshot.
Just like Google’s Pixels, Windows 11 is affected by the “aCropalypse”
This fault would come from processing of PNG files by Windows 11. When you take a screenshot and modify it, by cropping it for example, you might think that the size of the file will be lighter after the operation. It is not so. The theoretically erased data (since they are no longer visible) are in fact always saved in the file. A pirate with the necessary know-how can therefore reconstruct the original image.
According to Me Buchanan, who had discovered the vulnerability on the Google Pixel 7, the flaw is only exploitable on PNG files, even if JPG files are theoretically recoverable too. Microsoft has of course been informed of the problem, and there is no doubt that the company’s engineers are actively working on a fix. Bleeping Computer offers us a temporary solution to this problem “If you open an untruncated PNG file in an image editor, such as Photoshop, and save it to another file, the unused data at the end will be deleted, rendering the file unrecoverable”.
Source : Bleeping Computer
