Hi Jake, In message <_A4895@delegate-en.ML_> on 09/01/10(08:25:44) you Jacob Lundberg <pdeiqbdyi-pvjs3to62c66.ml@delegate.org> wrote: |One of the ways people try to prevent ftp port bounce attacks and |probing is to require in the FTP server that the PORT command must |specify the same IP as the originator of the control channel. Is this |possible with DeleGate? From the documentation, it seems like DeleGate |only supports turning the PORT command off entirely. Even if PORT is turned off, clients can establish active connections by using EPRT as "EPRT |1|10.20.30.40|12345|" for example. |Either of these two things would work while still allowing PORT commands: | |1) An option to ignore the IP given in a PORT command and silently use |the same IP as the control channel. | |2) An option to reject the PORT command if the IP address is not the |same as the one in the control channel. | |Both of these options would be non-RFC-compliant behavior, but several |security audit standards are requiring something of this sort. Thank you for your description of the problem. Maybe I should follow the following documents in CERT about "FTP Bounce." <URL:http://www.cert.org/advisories/CA-1997-27.html> <URL:http://www.cert.org/tech_tips/ftp_port_attacks.html> From version 9.9.8-pre13, DeleGate acts as your 2) by default. It can behave as 1) with an option FTPCONF="bounce:cb" ---- Manual.htm#ftp-bounce ---- bounce:{no|do|th|cb|rl} -- default: FTPCONF=bounce:no controls how to manipulate FTP Bounce. no -- reject any FTP Bounce do -- permit any FTP Bounce th -- don't care FTP Bounce (backward compatible) cb -- convert FTP Bounce to "EPRT |||port|" rl -- reject FTP Bounce by REJECT="ftp-bounce:*:clientHost" doepsv:sv use EPSV (instead of PASV) with FTP servers doeprt:sv use EPRT (instead of PORT) with FTP servers ------------------------------- Cheers, Yutaka -- 9 9 Yutaka Sato, CSDP <y.sato@delegate.org> http://delegate.org/y.sato/ ( ~ ) National Institute of Advanced Industrial Science and Technology _< >_ 1-1-4 Umezono, Tsukuba, Ibaraki, 305-8568 Japan Do the more with the less -- B. Fuller