When I see this my initial thought is that the gasket is leaking in the top corner just by the stud. This is then dripping down to the stud and appearing like the leak is coming from it. I would seriously doubt that the leak is coming from the stud itself, unless it is that loose to allow oil to come up.
I would clean up the area and then wrap some kitchen towel around the stud, also cleaning the surrounding area including under the cam gasket as best as possible. Then run the car for a bit and with a clean piece of kitchen towel dab around the area, checking for oil on the towel. This will give you a good idea of where the leak is originating from. With the car off take the towel from around the stud and see if there is any oil on it. I often run the car for a bit and use kitchen towel to dab around areas to check there is no oil leaking. The wife often moans about where all the towel is going.