Re: Is starting a user program on priv port via inetd dangerous ?
Graham Toal (gtoal@an-teallach.com)
Fri, 22 Jul 1994 14:15:02 +0100
My question is this: I own /home/dougmc/ircd/ircd, so I can change it
in any way I want. Is it possible to alter it in such a way that it
takes this open fd to port 194 and abuses it, perhaps uses it to spoof
a rlogin or rsh?
No, but what is theoretically possible is that someone could use ircd
to run arbitrary programs as the irc user. Even if you run it as a special
user and in a chroot shell, there's a small possibility of abuse... for
instance, say you run nntpd and have some private local groups you don't
want exported, then if someone ran a proxy nntp port bouncer, they could
access your local groups because the call would appear to be from a local
user rather than the real remote host.
However, if the rest of your system is set up properly, what you suggest
above is no more dangerous than giving strangers a guest shell. If you
allow outsiders on your machine anyway, it shouldn't be a problem. If
you think your machine is only ever used by trusted insiders, it could
be a problem.
G