Privacy Letterboxing leaking on MacBook Pro Retina Display
Categories
(Core :: Privacy: Anti-Tracking, defect, P3)
Tracking
()
People
(Reporter: 00.foggier-advent, Unassigned)
Details
Attachments
(1 file)
|
8.63 MB,
video/quicktime
|
Details |
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:129.0) Gecko/20100101 Firefox/129.0
Steps to reproduce:
I turned on
privacy.resistFingerprinting = true
privacy.resistFingerprinting.letterboxing = true
and resized my window, and looked at reported browser window size (tried multiple websites, but e.g. https://www.whatismybrowser.com/)
Actual results:
On the built-in 16-inch (3456 × 2234) retina display, letterboxing does function, but the reported browser window size is off by one pixel vertically. E.g. (1000x499, 900x799).
If the window is moved to an external 27-inch (2560 × 1440) display, the browser window size is reported correctly (1000x500, 900x800), but if it is moved back to the retina display, it is back to reporting the wrong result again.
This is leaking information and making the browser much more finger-printable. I would assume its uniquely identifying certain macbooks.
Expected results:
Letterboxing should have resulted in the reported browser window size being shown as it was on the external monitor, an increment of 100.
|
||
Comment 1•1 month ago
|
||
The Bugbug bot thinks this bug should belong to the 'Core::Privacy: Anti-Tracking' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.
|
||
Comment 2•1 month ago
|
||
I cannot reproduce the issue. Could you provide a screen recording so we can diagnose this? Thanks.
|
Reporter | |
Comment 3•1 month ago
|
||
I don't have access to my external monitor where its 'normal' right now, I'll add a recording on Thursday, but this is a recording on the inbuilt monitor showing the off by one. If I were to drag this to the other monitor, it would increase by 1 and be the number you would expect (800, 500, etc).
Description
•