Microsoft Dynamics CRM 4.0
CRM 4.0 does not provide a method for securing records at the field level. If a user has modify access to a record then they may change any field in the record.
Where field-level security is needed then there are workarounds:
- move the fields that need to be secured separately to a custom entity
- use a third-party add-on
- develop your own solution.
With regard to item 3, Microsoft has published a comprehensive document that describes the issues and is well worth a read. It can be found here:
Microsoft Dynamics CRM 2011
CRM 2011 includes field level security out of the box but only for custom fields.
Microsoft Dynamics CRM 2013
Microsoft Dynamics CRM 2015
Details to be aded