Procedure Grants
For database procedures, the only valid permission is the Execute permission, which allows the grantees to execute the procedure.
Granting permission to execute a procedure makes database queries contained in the procedure code available to grantees. Granting execute permission to a database procedure also allows grantees to create rules that trigger the procedure.
The Execute permission is an enabling permission. By default, execution is prohibited unless the permission is specifically granted. This permission is not enforced for the owner of the procedure.
Permission to create procedures in the database is described in Database Grants.