Regardless of the corruption, recent world championships have been a set number of games. Typically 24 games or something like that. If the match ends 12-12 extra games (in pairs) are played to determine the winner.

In this case 4 game matches would be a good option. If 2-2 keep playing pairs until a winner is found.

Once again, since some people disagree I suggest it be an option that the tournament organizer can choose, just as when setting up a friendly match.