Help! Can I sort this myself or do I need professional help?

[Dragonfly1000]

Hi, I have just moved into a 1930s property. With all the recent rain I have noticed that the bottom corner of the front bay window is leaking. Appears that the previous owners did a pretty nasty patch up job on this previously. I can't see where the water is coming in from outside. Does anybody have experience of this and can help provide any advice on how to deal with this?

 

[crank39]

Is that an aerial cable i see there, I'd check that first to se if the rain is flowing in along that, other than that check for shrunken silicone, any gaps in the area and also check above as water could be ingressing at the top and egressing lower down

 

[Gazman16]

Pics of the outside will be what we need to see