Please note: since this exploit only works when you do a server transfer, it is very hard to test, so it may not work with the aspects besides the one i used (or if its possible with other buffs)
I found this completely by accident, here it goes:
I was going to transfer to another server and I guess I still had Aspect of the viper on when I logged off. so when i signed on when the transfer was finished i still had the buff (although I didn't notice at the time) then when I put aspect of the hawk on, sure enough, aspect of the viper stayed and I had both aspects at the same time.
here is a pic of it if you don't believe me:
This is pretty useless unless you already plan on transfering, but it's still an exploit..
So Enjoy!