small-package/luci-app-filebrowser/root/usr/share/rpcd/acl.d/luci-app-filebrowser.json

{
	"luci-app-filebrowser": {
		"description": "Grant access to File Browser",
		"write": {
			"cgi-io": [ "upload", "download" ],
			"ubus": {
				"file": [ "*" ]
			},
			"file": {
				"/*": [  "list", "read", "write" ]
			}
		}
	}
}