In reply, UAE were all out for 108, with nine balls left, after 18.3 overs as Mark Watt and Safyaan Sharif each took three wickets. Scotland joined Namibia, Netherlands, Papua New Guinea and Ireland, who had already booked their places but are still competing for the winner's trophy in UAE.
The 14-nation tournament decides which six nations complete the 16-team field for the World Cup in Australia from October 18 to November 15 next year. The final spot was being decided between Hong Kong and Oman in Dubai later.
Scotland had struggled in group play and finished only fourth in their seven-team group. "Not gone our way on this trip but nice to get over the line in the must-win game," said 'man of the match' Munsey.
Hosts UAE, whose squad had been diminished by the suspension of four players after corruption investigations, only narrowly missed an automatic World Cup berth when they finished third in their group on net run rate.