It's not plausible. It's a very unreliable attack vector, but what makes it completely pointless is in order to even set it up, you already need permission to

It's not plausible. It's a very unreliable attack vector, but what makes it completely pointless is in order to even set it up, you already need permission to edit the user's bash profile, and if you can do that, then you don't need LD_LIBRARY_PATH.