I take it it is with a private landlord rather than student accomodation services.
It would be difficult to get out of the contract if it has been signed for a set period. Your son could leave but would, depending on the contract, be likely to be liable for the remaining year's rent and could be pursued through the courts for it accruing additional costs.
Bearing in mind it's only October I would think he owes a substantial amount and if others are thinking the same think about leaving then the Landlord would be more likely to take action.
Did he pay a deposit which could be offset?
Some landlords will accept someone leaving if a new tenant is found although with the problems stated it doesn't look very likely.
Has your son spoken to the landlord and to the university about it, they should have someone in student services, usually in the students union who may be able to provide advice and assistance.
He could also try to the local council to see if thay can do anything, especially in the event he is a housing authority tenant.
I'd say first stop would be the students union to get someone who can advise and help liaise with other parties such as the landlord, council, police etc...