Permission was granted because of the Lancashire sides injury crisis and Hudson has joined on a one month loan deal.
Oldham chief executive Alan Hardy told the clubs official website: "As we are in administration we are unable to undertake any transfer dealings. There is an embargo on us.
"However our current situation with players' injuries meant we had to ask the League if they would allow us to bring in a player.
"They were understanding of our position and gave us the green light to proceed on this occasion."