(2R,3S)-2,3-dihydroxy-2,3-dihydro-p-cumate + NAD(+) = 2,3-dihydroxy-p-cumate + H(+) + NADH Aromatic compound metabolism; p-cumate degradation; acetaldehyde and pyruvate from p-cumate: step 2/7. Belongs to the short-chain dehydrogenases/reductases (SDR) family.