COMMAND
gopher
SYSTEMS AFFECTED
Systems running gopherd.
PROBLEM
Gopher is a really simple protocol. It runs on TCP on port 70.
Basically it works like this.
Client Connects
Client Sends: requesteddoc<CRLF>
Server Sends: XName of documet <TAB> path to document <TAB> site <TAB>
port <TAB> +
.. and repeats through an index list ..
blah...
If you send "ftp:ftp.site.com@/" as your requested document, the
gopher server logs on to the ftp site anonymously and acts as a
proxy. This is no secret or magic trick, it seems as though alot
of gophers link into FTP servers. That makes your ftp a hell of
a lot more anonymous.
It seems like a relatively trivial thing to access an intranet
ftp server on the other side of a firewall if you can make it
look like its coming from the gopher server... after all .. it is.
So Basically:
gopher://gopher.anysite.com/ftp:ftp.anothersite.com@/ makes
gopher.anysite.com act as a proxy for ftp.anothersite.com
Credit for this goes to Ben Camp.
SOLUTION
Don't run GopherD on your firewall. This is probably a
configuration issue, but since i'm not aa gopher monger I
wouldn't know.