This hadith has been narrated by Ibn Abu Fudaik and Dabbik b. 'Uthman with the same chain of transmitters and they observed:Private parts of man are the nakedness (which is concealed).
وَحَدَّثَنِيهِ هَارُونُ بْنُ عَبْدِ اللَّهِ، وَمُحَمَّدُ بْنُ رَافِعٍ، قَالاَ حَدَّثَنَا ابْنُ أَبِي فُدَيْكٍ، أَخْبَرَنَا الضَّحَّاكُ بْنُ عُثْمَانَ، بِهَذَا الإِسْنَادِ وَقَالاَ - مَكَانَ عَوْرَةِ - عُرْيَةِ الرَّجُلِ وَعُرْيَةِ الْمَرْأَةِ .
Muslim
The Book of Menstruation • Hadith 91