How to repair exterior door/jam and exposed cinder block
I have an exterior door that was put in by the previous owner and in these winter months I have noticed an 8 x 10" area of frost on an interior wall. I have gone outside to investigate and have found that there appears to be a gap in the masonry where the cinder block was cut into to accommodate the door (please see the attached photo, gap is to the left of the door). I believe this is partly where my frost problem comes from.
Does anyone know what can be done on the exterior? We do plan to insulate the interior walls in this back entry area once spring arrives and would like to get this problem solved at the same time if we can. Mind you, we are new to tackling home repairs but are eager to learn if this is something we can do ourselves.
Appreciate any help!
Extra info: House was built in 1910s, cinder block foundation, wood frame on top. Door in question exits onto a poured patio slab.