The following picture shows what are the current permissions requested by the Microsoft Dynamics CRM Connector V2 when authenticating:
Access Common Data Service as you
Allows the application to access Common Data Service as you.
Sign you in and read your profile
Allows you to sign in to the app with your organizational account and let the app read your profile. It also allows the app to read basic company information.
In the future, these permissions might change to accommodate new features / API changes.