Zero Trust Always Verify

"Never trust, always verify" 

is the foundation of the contemporary cybersecurity model known as "Zero Trust." Zero Trust makes the assumption that threats can come from both inside and outside the company network, in contrast to traditional security models that assume everything is safe within the network. 

Keyword: Never trust to anyone (mobile, laptop, application, device, user, network etc) by default

Also See, how a payment solution compromised  

Consequently:

1- It is necessary to continuously authenticate and authorize each user, device, and application.

2- Not only network location, but also identity, context, and risk are taken into consideration when granting access.

3- To reduce attack surfaces, it employs micro-segmentation, least privilege access, and ongoing monitoring.

4- Inventory does not means hardware or softwares inventory. Make sure all authorization & authentication rights removed as the user resiged

Also See HybridPetya Ransomware Bypasses UEFI