app/models/spree/user.rb in spree_auth_devise in Spree 1.1.x before 1.1.6, 1.2.x, and 1.3.x does not perform mass assignment safely when updating a user, which allows remote authenticated users to assign arbitrary roles to themselves.
Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.