The Messenger of Allah (ﷺ) wiped over the socks.

Another version adds: "On the back (upper part) of the socks."
Sunan Abi Dawud Book 1, Hadith 161
← Previous Hadith The Messenger of Allah (ﷺ) performed ablution and wiped over his shoes and feet.

Abbad (a sub-narrator) said: The Messenger of Allah (ﷺ) came to the well of a people. Musaddad did not mention the words Midat (a place where ablution is performed), and Kazamah (well). Then both agreed on the wording:"He performed ablution and wiped over his shoes and feet."

Sunan Abi Dawud Book 1, Hadith 160 Next Hadith → If the religion were based on opinion, it would be more important to wipe the under part of the shoe than the upper but I have seen the Messenger of Allah (ﷺ) wiping over the upper part of his shoes.

Sunan Abi Dawud Book 1, Hadith 162