In CSF rhinorrhea CSF from middle cranial fossa reaches the nose :

CSF from anterior cranial fossa reaches the nose cribriform plate, roof of ethmoid air cells or frontal sinus. CSF from middle cranial fossa reaches the nose sphenoid sinus. Fractures of temporal bone result in leakage of CSF into the middle ear and escapes through eustachian tube into the nose (otorhinorrhoea).