-
Notifications
You must be signed in to change notification settings - Fork 41
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge branch 'master' into hidden-download-detection
- Loading branch information
Showing
2 changed files
with
39 additions
and
25 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,39 @@ | ||
+++ | ||
title = "Download Bar" | ||
description = "" | ||
date = "2024-04-23" | ||
category = "Historical" | ||
abuse = [ | ||
"Downloads" | ||
] | ||
defenses = [ | ||
"Deprecation" | ||
] | ||
menu = "main" | ||
+++ | ||
|
||
In Chromium-based browsers, when a file was downloaded, a preview of the download process appeared in a bar at the bottom, integrated into the browser window. By monitoring the window height, attackers could detect whether the "download bar" opened: | ||
|
||
|
||
```javascript | ||
// Read the current height of the window | ||
var screenHeight = window.innerHeight; | ||
// Load the page that may or may not trigger the download | ||
window.open('https://example.org'); | ||
// Wait for the tab to load | ||
setTimeout(() => { | ||
// If the download bar appears, the height of all tabs will be smaller | ||
if (window.innerHeight < screenHeight) { | ||
console.log('Download bar detected'); | ||
} else { | ||
console.log('Download bar not detected'); | ||
} | ||
}, 2000); | ||
``` | ||
|
||
{{< hint important >}} | ||
This attack was only possible in Chromium-based browsers with automatic downloads enabled. In addition, the attack can't be repeated since the user needs to close the download bar for it to be measurable again. | ||
{{< /hint >}} | ||
|
||
### Fix | ||
Chromium moved away from a download bar, They explain why in the blog post [Redesigning Chrome downloads](https://blog.chromium.org/2023/08/redesigning-chrome-downloads-to-keep.html) it helps create a clearer separation of trusted browser UI from web content among other reasons. |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters