Has a World Cup game ever ended 17-0?
Exactly once. On June 2, 1997, Iran beat Maldives 17-0, and no World Cup game before or since has ended that way. When it happened it was a scorigami, the first 17-0 in league history.
That makes 17-0 the 43rd most common final score out of 53 that have ever occurred in World Cup. One point away, 18-0 has happened never and 17-1 has happened never.