1871012 - window.prompt() with long description hides fullscreen notification, leads to spoof

Status: RESOLVED DUPLICATE of bug 1798798

(Fenix :: General, defect)

Description

[Hafiizh]

Attachment: video6057586934719451115.mp4

I found a vulnerability in firefox android where a window prompt with a long description can cover fullscreen notifications which can lead to spoofs. this is same like : https://bugzilla.mozilla.org/show_bug.cgi?id=1798798

steps to produce

1. open pocalert2.html
2. Click the open to google button
3. Then a dialog prompt window appears with a long description and covers the fullscreen notification
   4 then click ok

OS: Android 12 (Samsung M31)

i attached the poc video files.
thank you

Comment 1

[Hafiizh]

Attachment: pocalert2.html

Comment 2

[:Gijs (he/him)]

AFAICT in the recording, full screen is exited when the prompt appears, showing the address bar. So I don't see how this is a spoof?

Comment 3

[Daniel Veditz [:dveditz]]

On my phone, which must be a little taller than the reporter's, I see the fullscreen toast below the prompt. I also see the text box of the prompt which isn't visible in the video (doesn't make a difference to the PoC, just more evidence for a height difference). But those are besides the point. once the prompt is closed there's no spoofing of the URL bar.

How is this not a straight dupe of bug 1798798 (which is fixed)? The only difference between the two testcases is a change to call the prompt() from a timeout, but that doesn't seem to make any difference. I get the same results from the testcases in both bugs.

Comment 4

[Hafiizh]

I'm sorry, it's true that it goes out of full screen mode