Is it permissible to apply masah over the socks worn on the khuffs?
It is permissible to apply masah over socks worn on the khuffs provided that they are thin and they pass the water through themselves when one applies masah (wipes) over them. If water does not pass through them, masah will not be valid (Marghinani, al-Hidayah, I, 201; Mawsili, al-Ikhtiyar, I, 92, 93).
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS