This is postauth RCE so to continue you’ll need password of the admin user (in this case – “Manager”) As you will see below to achieve RCE in latest version we need to go to the Dashboard (as logged-in admin user) and click ‘Change’ to change the hostname. But you won’t see your asd3 file in /tmp/ now. You need to wait a little bit for the application to refresh (after each of those requests)”]
Source: https://code610.blogspot.com/2020/03/rce-in-artica-426.html