What prevents an attack on Postfix through its named pipes by writing bogus data to them? I see on my system that they permit write access to other. I wonder if that opens Postfix to DoS or some other form of attack.
prw--w--w- 1 postfix postdrop 0 Nov 28 21:13 /var/spool/postfix/public/pickup
prw--w--w- 1 postfix postdrop 0 Nov 28 21:13 /var/spool/postfix/public/qmgr
I reviewed the pickup(8) and qmgr(8) man pages, and searched here and elsewhere, but failed to turn up any answers. I found no information about the named pipes themselves: not even what’s normally written to them, much less how they are secured. The words pipe or fifo do not even appear in the documentation.