I have lost my phone and all my contacts are stored in the CM Security cloud vault. How to retrieve those contacts?
Retrieving your contacts won't be a problem if you have a backup in the CM Security cloud. All that you should do is to install the application on your new phone, login to your account and restore your contacts from your cloud backup.
Install the application: https://play.google.com/store/apps/details?id=com.cleanmaster.security&hl=en
You can use a data recovery tool to restore the lost or deleted data.
The whole operation can be done on pc, and the lost data can also be recovered on pc.
have a look at this guide, how to restore deleted contacts.
This tool can recover android files easily.