Kind of, but also kind of not. I mean if someone can smuggle a file into some random directory, chances are they have enough access to write directly to the "correct" folder to begin with. Personally I wouldn't execute or otherwise load any sort of executable content from a non-root directory (although certainly there are many people who wouldn't even think twice before doing such a thing). So it really just boils down to having a sane security-policy. Restrict searches with something like "path -d /usr *" and you are guaranteed not to scoop-up something that was world-writable in the first place. In fact in the example given in the README, that is precisely how that would have worked. Both /lib32 and /lib64 are owned by "root" and hence not a concern.