No idea if it counts as exploit or if its just a glitch.
Join LFR 2nd part, sit in a cannon and go AFK.
Enjoy the rage, because they are unable to defeat Galakras and the waves will occur infinite (you can't engage Galakras without both cannons, infight cannot be kicked).
Might be bannable offense, so take care.
Had a 90 minutes fight until the tanks decided to leave, so it could become quite entertaining except if they decide to wipe.