§1. To be promoted to an ecclesiastical office, a person must be in the communion of the Church as well as suitable, that is, endowed with those qualities which are required for that office by universal or particular law or by the law of the foundation.
§2. Provision of an ecclesiastical office made to one who lacks the requisite qualities is invalid only if the qualities are expressly required for the validity of the provision by universal or particular law or by the law of the foundation. Otherwise it is valid but can be rescinded by decree of competent authority or by sentence of an administrative tribunal.
§3. Provision of an office made as a result of simony is invalid by the law itself.
Source: Code of Canon Law (Vatican.va)