We've recently implemented this in JP 10.9. Simply uncheck the Allow box and push the profile to your users. Once the profile is received, the drives are prevented from mounting as storage.

Doesn't work for me, Ive applied the configuration and unticked external drives and it still mounts a drive.

@jonathan.rudge Have you restarted the Mac after pushing the profile? Or at least logged out and back in again? It's been a while since I tried this setting, but IIRC it didn't take effect until restart/login.

I use that, here is a screen grab of my configuration.

Yep I was tried but there is any way to know the extension attribute to aware of the blocked status "USB"

Any way to disable USB mass storage device in macOS 11 without third party software, may be script or JAMF proposed a new kind of solution

I was messing around with this, and noticed that in Read Only Access Iphones can still get files transferred to them.

Has anyone else experienced this or found a way to block this?   The only change I have in my config policy is External Disks are set to read only.

Is this going away on Big Sur and above ?

It already gone and now we need third party software to control USB devices, as I could remember symantec is doing the job

Jamf has announced support for this in Jamf Protect:

https://www.jamf.com/blog/jamf-protect-beta-new-usb-storage-controls-jnuc-2021/

Version 2022.1 of Google's Santa tool added support for USB Mass Storage blocking: https://github.com/google/santa

Jamf Protect is currently not working for me to disable USB ports.