Water leakage causing smell

Hi, There is an unpleasant smell from the pipe of hand wash basin. Something like plastic or glue. i have no idea what it is. However, my amateur inspections revealed little water leakage at the meeting point of the pipe from basin and the floor. The rubber plastic/casket was a bit loose and the glue (holding it) was loosened. i tried to cover it with silicone glue, which worked temporality, but the smell came out somewhere else. i need someone to inspect and fix the issue. Thanks.