Mo. Rev. Stat. § 525.170

Such judgment by default may be proceeded on to final judgment, in like manner as in case of defendants in other civil actions; but no final judgment shall be rendered against the garnishee until there shall be final judgment against the defendant, and in no case for a greater amount than the amount sworn to by the plaintiff, with interest and costs, or for a greater amount than the garnishee shall appear to be liable for to the defendant.