The Hardware Bridge
Google Chrome features an advanced API called WebUSB. This API allows websites to bypass the operating system’s standard abstraction layers and communicate directly with physical USB devices plugged into your computer (such as 3D printers, microcontrollers, or specialized medical equipment). While incredibly powerful for web-based hardware flashing tools, it represents a massive security risk. Malicious websites can potentially exploit this direct bridge to probe your USB ports, extract data from attached hardware, or flash malicious firmware. To lock down your physical ports, you must completely paralyze this API.
How to Block USB Device Access Globally
You can permanently sever the browser’s ability to see your USB hardware via Chrome’s Site Settings.
- Open the Google Chrome desktop browser.
- Click the three vertical dots (⋮) in the top right corner and select Settings.
- In the left-hand sidebar, click on Privacy and security.
- In the main window, click on Site settings.
- Scroll down to the “Permissions” heading and click to expand Additional permissions.
- Click on USB devices.
- Under the “Default behavior” heading, select the radio button for “Don’t allow sites to connect to USB devices.”
A Sandboxed Browser
The change takes effect instantly. Google Chrome will completely sever its internal connection to your motherboard’s USB controller hub. The browser is now permanently blind to any physical hardware you plug into your machine. If a website attempts to execute a WebUSB script to scan your ports or connect to a device, the API call will instantly auto-reject in the background, returning a null value. This guarantees that unverified web code can never directly interact with your physical peripherals.