Fixing loose connections in the pipes typically tackles the problem, according to Do It Yourself. Inspect the seals and pipes where necessary by detaching the drain basket and drain pipe with a wrench to unlock the washer. If any cracks are seen on the seals and pipes, then replacement is necessary.
Do It Yourself further notes that dismantling the drain is necessary for leaks under kitchen sinks caused by blockage. Remove the strainer, which is part of the sink basket, with pliers. Take out the drain basket and apply sealant underneath it. The water basin should be sealed at the top as well with a caulk gun. The parts should be reassembled, and the sealant should be smoothed. Reassemble the drain pipe with extra sealant and tighten the connections as well. Sealants typically take up to 3 days to dry. If there are leaks in the pipes, then reapply the sealant where necessary.
SF Gate mentions that the method of fixing a leaky sink depends on the type of sink, but common solutions include fixing gaskets or the washers. Tightening the compression fittings for shut-off valves is another option, and adjusting faucet connections with locking pliers may be necessary. An auger should be used for drain-line blockage. Dismantling and applying plumber's putty on the sink drain works as well for blockages.