Remove the drawer from the furniture piece.
Insert a tape measure along the drawer guide to the back wall of the furniture. Measure from the front face to the back wall. Measure the length of the drawer from the front face to the back.
Subtract the drawer length from the cavity length. This is the thickness of the board for creating a bumper.
Cut a piece of wood to this thickness and 3 inches long.
Tape the block of wood to the back of the drawer and insert the drawer into the furniture. The block should halt the drawer when it touches the back of the furniture. Make sure the drawer stops flush with the furniture face. Sand down the block until it fits perfectly.
Apply construction adhesive to the wood block and glue the block to the back center of the drawer. Clamp the block in place until the adhesive dries.