Malicious USB devices pose a significant danger to all laptops. Rubber Ducky attacks, which are powered by flash drives that appear harmless, can imitate your keyboard and take control of your system.
You can currently disable individual USB ports if you are concerned about these attacks. However, Google is currently testing a new Chrome OS feature that will lock Chromebook USB ports when their screens are locked.
In September, Chrome Story discovered this feature in the Chrome OS source code. In addition, the blog discovered just over a week ago that users will be able to “whitelist” trusted devices.
The feature is currently available in Chrome OS Canary builds. You can test it on your Chromebook using the chrome:/flags/#enable-usbguard Chrome OS flag. Keep in mind that Canary builds, which are used to test many new Chrome features, are more likely to contain bugs and glitches.
If you are not a Canary user, the feature will likely be made available to the general public shortly.
However, if you want to leave your Chromebook out in the open without fear, this will not be sufficient. You should also restrict sign-in to your own Google account so that thieves cannot use their accounts to reactivate the USB ports. (Also, you may want a laptop lock.)