Information
Guest users can be set up for those users not in your tenant to still be granted access to resources. It is important to maintain visibility for what guest users are established in the tenant.
Rationale:
Periodic review of guest users ensures proper access to resources in your tenant.
NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.
Solution
To view guest users, use the Microsoft 365 Admin Center:
Log in as an administrator
Navigate to the Users and Guest Users
Review the list of users
To verify Microsoft 365 audit log search is enabled, use the Microsoft Online PowerShell Module:
Run Microsoft Online PowerShell Module
Connect using Connect-MsolService
Run the following PowerShell command:
Get-MsolUser -all |Where-Object {$_.UserType -ne 'Member'} |Select-Object UserPrincipalName, UserType, CreatedDate
Review the list of users