Red Hat Bugzilla – Bug 16134
Command line FTP clients should default to PASV transfers not PORT transfers
Last modified: 2015-03-04 20:08:37 EST
The subject says it all really.
Both /usr/bin/ftp and /usr/kerberos/bin/ftp are affected.
I guess I'd better explain why I'd like this changed ;-)
Check out http://cr.yp.to/ftp/security.html for a succint summary of the
NOTE that most other RedHat shipped FTP clients pick the better PASV
default. Some examples are: gFTP, Netscape, NcFTP
As of RFC1123 (Requirements for Internet Hosts -- Application and Support,
October 1989) every FTP MUST implement the PASV command, and as pointed out,
PORT is really not save.
Therefore i've changed the default behaviour of the command line ftp client to
be in passive mode and the -p option will still work, although won't do much
The change is reflected in the usage and manpages as well.
The version of ftp from /usr/kerberos/bin has now had its behavior changed as
Guys, superb effort and turnaround time.
One clarification to make
It seems Netscape defaults to PORT not PASV.
I think the "PASV default" is Mozilla.
gFTP and NcFTP use PASV default as I said.
Oh well. Netscape is netscape, and there isn't anything we
can do about it. :(
Actually.. it looks like even netscape defaults to PASV
All the important FTP clients now default to PASV. This is
very cool in combination with the new "high security" firewall option.