topic Re: How to forbid the command ftp > ! /bin/ksh in Operating System - HP-UX

How to forbid the command ftp > ! /bin/ksh

Manceau — Mon, 28 Jan 2002 17:24:59 GMT

Hi,

I want to forbid /bin/ksh when a user is on ftp prompt.

What can I do ?

Re: How to forbid the command ftp > ! /bin/ksh

harry d brown jr — Mon, 28 Jan 2002 17:28:22 GMT

Manceau,

What OS are you running?

live free or die
harry

Re: How to forbid the command ftp > ! /bin/ksh

Bill Hassell — Mon, 28 Jan 2002 17:34:57 GMT

Using the ! to escape ftp is a server setting. On the server side, look at the ftp daemon configs to forbid shell escape (and perhaps the site and quote commands too).

Re: How to forbid the command ftp > ! /bin/ksh

harry d brown jr — Mon, 28 Jan 2002 17:47:55 GMT

In 11.x, I'm not sure you can, but maybe you want to look into using tftp if you can't trust your users? Plus you have the pipe commands, like ls -l "| more", where more allows you to "escape" to a shell.

live free or die
harry

Re: How to forbid the command ftp > ! /bin/ksh

S.K. Chan — Mon, 28 Jan 2002 17:57:48 GMT

You can try this ..

Set the SHELL variable to /bin/false in your user environment. That should restrict the use of all "!" command within ftp.

Re: How to forbid the command ftp > ! /bin/ksh

Steven Sim Kok Leong — Mon, 28 Jan 2002 18:32:45 GMT

Hi,

Remove /bin/ksh from /etc/shells will forbid a user with the login shell /bin/ksh from FTP'ing into the system.

Hope this helps. Regards.

Steven Sim Kok Leong

Re: How to forbid the command ftp > ! /bin/ksh

Christopher Caldwell — Mon, 28 Jan 2002 19:55:21 GMT

When they run
ftp > ! /bin/ksh

the shell is executed on the local host; thus ftpd server configs aren't in play:

man ftp

! [blah] Invoke a shell on the local host.

I suppose you can do things like restrict users from having a valid shell (/usr/bin/false, /usr/bin/ftponly), but those are generally server side configurations, and I'd have to wonder (if you limit them on the client side), how they got to the ftp command to begin with.

Re: How to forbid the command ftp > ! /bin/ksh

Manceau — Tue, 29 Jan 2002 13:40:13 GMT

Thank you for your help.

Philipe MANCEAU.