Depends. Can an attacker introduce files? If so, he can probably introduce collisions. In most uses of a hash, that's an issue—a performance (DoS) issue if noth

Depends. Can an attacker introduce files? If so, he can probably introduce collisions. In most uses of a hash, that's an issue—a performance (DoS) issue if nothing else. If the application was just looking for a longer CRC/Adler32/etc. and not depending on the hash to be strong against attack, then MD5 wasn't an appropriate choice in the first place, as its much slower than need be. But the security problems are irrelevant.