Yes, I suppose I shouldn't have assumed you would read the rest of the thread for context. If you are going to give someone shell access, there are a million ways they could DoS you, so don't give people shell accounts on an important server. But that doesn't have anything to do with perl bugs.
Not entirely sure where you're going with the DB thing. If you have a Perl program that mediates access to a database that's not accessible any other way, then yes, a perl bug could compromise your database. But in that situation, the program has "elevated privileges" in a sense, even if that isn't implemented with OS-level permissions.