Prevent USB writes and restrict external media on macOSSolved

Hi @aurora,

You can configure this using the Media Management policy for macOS devices.

To set it up:

1. Go to Policies and create a new policy, or open an existing macOS policy.
2. Navigate to macOS > Security > Media Management.
3. Click Configure.
4. In the External Media section, choose the setting based on the level of restriction required:
   • To block USB/external media completely, select Deny all use of external media. This prevents external drives from mounting, so both read and write access are blocked.
   • To allow USB drives but prevent copying data to them, enable Allow use of external media as read-only.
   • If required, you can also configure the policy to require administrator credentials for mounting or writing, depending on the available option in your policy configuration.
5. Go to Policy Targets, assign the policy to the required macOS devices or user groups, and save the policy.

After the policy is applied, the restriction will take effect on the targeted macOS devices according to the selected external media setting.

Regards,
Sienna Carter
Hexnode UEM

if I choose Deny all use of external media, users won’t even be able to open files from a USB drive, right? I only want to stop copying company files out to USB, not block reading completely.

Hi @aurora,

Deny all use of external media blocks the external media from being used, so it is suitable when you want to fully prevent USB storage access.

For your requirement, use Allow use of external media as read-only. That allows users to access files already present on the external drive, but prevents write operations from the Mac to the USB drive.

Regards,
Sienna Carter
Hexnode UEM