Subject: PASV ftp ports

From: Matt Engen <[email-masked]>
Date: Tue, 01 Sep 1998 18:33:48 -0700

Hi,

I would like to restrict PASV ftp to a given port range.  It is my
understanding
that when the client sends the PASV command, the server opens a random
high numbered port and informs the client of the port number. The client
then
does and active open to the server on that specified port.  This is a
problem
when the ftp server is located behind a firewall.  The incoming
connection
is blocked. For security reasons, I would much rather open up a "range"
of
ports for inbound traffic rather than anything over 1024. Can this be
done with
wu-ftp? Am I missing something else?

According to RFC 1579

  "Further precautions can be taken by modifying the FTP server so that
   it only uses very high-numbered ports for the data channel.  It is
   comparatively easy to ensure that no dangerous services live in a
   given port range.  Again, this is feasible because of the small
   number of servers. "

I have read through various READMEs and the FAQ and do not see it. A
pointer to the correct document would be greatly appreciated.

Thanks.

-Matt

---

From: Gregory A Lundberg <[email-masked]>
Date: Tue, 1 Sep 1998 21:45:01 -0400 (EDT)

On Tue, 1 Sep 1998, Matt Engen wrote:

> I would like to restrict PASV ftp to a given port range.

Get the VR6 patched version of the daemon from:

  ftp://ftp.vr.net/pub/wu-ftpd/

Or dig through the mailing list archives at the Resource Center for the
specific patch.

The location of the latest version of wu-ftpd can be found in the 
directory
 
      ftp://ftp.academ.com/pub/wu-ftpd/private/
 
You can't see the directory contents, so read the message informing you
of the actual filename to retrieve. It's there.
 
wu-ftpd Resource Center:  http://www.landfield.com/wu-ftpd/
wu-ftpd FAQ:              http://www.cetis.hvu.nl/~koos/wu-ftpd-faq.html
wu-ftpd list archive:     http://www.landfield.com/wu-ftpd/mail-archive/

----

Gregory A Lundberg		Senior Partner, VRnet Company
1441 Elmdale Drive              [email-masked]
Kettering, OH 45409-1615 USA    1-800-809-2195