Ghast oversight on Mob Griefing

Something that has been bugging me lately has been working in the nether with the presence of Ghasts; Ghast fireballs bypass No Mob Griefing rules, most particularly this is noticeable on netherrack which still explodes upon contact with a ghasts fireball, and burnable items which are still set on fire by them.

More broadly, this could be true for other things that I simply have not noticed. Ghasts are the only culprit I've come upon though