The best fix would, of course, to get a new section.

If you can't find a replacement section, then you can maybe rewrap the ferrule. (I'm going to assume that it's a female ferrule?)

The success of rewrapping the ferrule will depend on the size of the crack.

Here's what I would do:
I'd remove the old epoxy and wrap to get a good look at the crack.
If you can get some superglue in the crack, that might be good. BUT you want to make sure that the glue would not interfere with the male ferrule's fit.
I'd measure how far the male section fits up into the ferrule. I would start my wrap just above that point.
I would also use some pretty tight tension on the thread while wrapping it.
Then go over it with a few coats of epoxy.

Maybe some of the folks might have some better tips.