The Board has to work it out. Not every issue should be addressed in the bylaws.
Secondly, I think it needs to be defined that while a Director may hold multiple positions, the Chair, Secretary and Treasurer must be different Directors for the sake of transperancy...If the Chair was Treasurer too it would not be too healthy IMO even if realistically its not that plausible for a dishonest person to be entering the BoD that easily...