I had created a while back, just checked it and works great on CRM 2013 version as well.

User Cloner for Dynamics CRM 2011

User Cloner for Dynamics CRM 2011 is utility for all CRM administrators, consultant who have to deal with user issues on CRM 2011 and want to check whether user has proper access by replicating his security role permissions to another user. It is also useful when all security allocations of a user need to be assigned to other user in CRM 2011. It allocates the following from a source user to any target user:

· Map Source User Business unit to Target User

· Map Source User Security Role to Target User

· Map Source User Teams to Target User

· Map Source User Field Security Profile to Target User

· Remove existing Security Role of Target User

· Remove existing Teams of Target User

· Remove existing Field Security Profile of Target User

  **Using Map Source Business Unit will also change all records owned by source user to target user in the business unit**

Codeplex link : http://userclonerfordynamicscrm2011.codeplex.com/