We have purchased a EMS licence from a vendor, Does he able to revoke our license remotely ?

Typically your license is perpetual meaning once you purchase it, it's yours and your site will work with that license if you choose to purchase maintenance or not. That being said, some partners rent licenses and sell them under different terms (terms that aren't really Kentico supported).

You might check the feature matrix to see the differences. You can also contact sales [at] kentico [dot] com and have them check into your license based on your domain name and they may be able to help you further if you're partner is not helping you.

Thank you Brenden for the answer.

I actually want to know does he able to revoke our licences remotely ?

Without accessing our hosting server and of course without CMSDesk access ?

And does Kentico validates license against any servers or Database ?

He told us that he can disable our license from Kentico site.

No he can't revoke your licenses remotely, unless he can access at least the database directly. I would change the database username and password as well as change the information in the Kentico web.config file as well. I do not believe there is any validation. It is perpetual for the version you have a license key for. I would recommend contacting Kentico directly and they can look up your license key and give you the details and your options.

Obviously if he has built in a custom back door, he will be able to gain access. I have ran into this at least on one occasion.

Thank you

It's a relief

I will check again our system for any sign of back door .

All of this is dependent on where the site is hosted and if they vendor has access to the file system, database or website admin. If they do, they can do about anything they want. If they don't then as long as your license was generated as a non-expiring license then it's not an issue. You can check this license by going to the License app in v8 or Site Manager>Licenses in v7 or earlier.

I'd check the user database for any sign of those users as well. Make sure they don't have access to the server, website, or file system (ftp, sftp, etc). If you're at all concerned, then you might want to attempt to export your site. If they set the site up properly then you will get almost all of it. If they didn't then you'll be short on some of the items.