Answer
Assign priorities to the groups around top central carbon: OH>CHO>CHOHCH2OH>H. This gives S configuration. Assign priorities to the groups around bottom central carbon: OH>CHOHCHO>CH2OH>H. This gives S configuration.
Work Step by Step
However, since the 4th group H is on a wedge, the configuration needs to be reversed. So the configuration for both carbons is actually R.