The ruling of mudharibah is that one person invests and the second one does labour and the profit is distributed as per the contract basis. In case of loss, first it is compensated from profit, then from capital amount. If the mudharibah is carried out accordingly, it is lawful according to shariah and there is no exploitation of the investor.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband