Should /bin/ksh work without the controlling TTY?

I’ve found a frightening mis-feature in my ssh-1.2.33 port to QNX4:

  • no matter if I put “no-pty” option on the user key (which should prevent
    the shell access), I’m still able to get the shell via “ssh user@host
    /bin/ksh” type of command.

The SSH server, when executes a command, does not allocate the tty. But if
I try the above - I get a sheel session which works as usual (the only
difference is no shell prompt seen at all).

Now I wonder - is it a port’s fault or /bin/ksh’s feature?
Can someone try this at home (on another UNIX box)?


OpenSSH people relieved me with saying that “ssh user@server /bin/sh” is
possible on other UNIXes too.
To solve the problem they advise using the “restricted shell” or “rsh”.
Is there such a thing for QNX4?