Sayyidina lbn Abbas (RA) said that he heard Allahs Messenger (SAW) say, “If one who assumes the ihram does not have the lower wrapper theu he may wear the trousers. And if he does not have sandals, he may wear socks.
[Ahmed5075, Bukhari 1740, Muslim 1178, Nisai 2668, Ibn e Majah 2931]