Em Wikitravel :
Dubai Airport currently has three passenger terminals. Terminals 1 and 3 are directly connected with a common transit area, with airside passengers being able to move freely between the terminals without going through immigration, whilst Terminal 2 is built on the opposite end of the airport. For transiting passengers, a shuttle service runs between the terminals, with a journey time of around 20 minutes from Terminal 2 to Terminal 1, and 30 minutes to Terminal 3.
Portanto, parece que existe um meio de ficar entre os terminais, se você é um passageiro em trânsito, mas você tem que pegar o ônibus, não andar.