Cast soil stack leaking from clay fitting in Kitchen?

The cast soil pipe has started leaking from the clay fitting where it joins the cast pipe. The pipe in internal through the house. There is concrete around the clay fitting and only part of the crack can be seen. Is there an easy way to fix it other than putting a new UPVC external soil pipe or can I replace the cracked fitting.

Would the cast soil pipe be supported so the leaking fitting can be smashed away and replaced ?