Information gets leaked with JavaScript

[firstfault]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Certain information is leaked although the user agent is spoofed, even the real user agent by using JavaScript.

Steps to reproduce

1. Go to CreepJS Workers page
2. Your real operating system will be shown & real user agent on the main page

Browser

Chrome

Extension version

4.3.1

Anything else?

Test it with https://abrahamjuliot.github.io/creepjs/
The browser used is Ungoogled Chromium