Drips Network lost 24882.99 DAIs due to integer conversion vulnerability

According to SlowMist security alert, there is an integer type conversion vulnerability in the give function of Drips Network's DaiDripsHub contract, resulting in 24882.99 DAIs being stolen. The vulnerability lies in the unverified upper limit of the value when converting uint128 amt to int128. The attacker reverses the flow of funds by passing in a specific value, resulting in the depletion of reserve funds.