[sane-devel] Scanning via net interrupts

Henning Meier-Geinitz henning@meier-geinitz.de
Mon, 18 Nov 2002 23:45:56 +0100


Hi,

On Mon, Nov 18, 2002 at 12:48:53PM +0100, Elmar Fähndrich wrote:
> I used to scan via intranet but since I made a few security changes on my 
> server (harden_suse yes) the scan process interrupts and freezes .

Basically, the data transmission doesn't start at all.

> With saned -d128 I get during scan:
> [saned] start_scan: using port 11323 for data
> [saned] process_request: waiting for data connection

and waits and waits...

> before I haven't used tcpd but after hardening it only worked that way.

I don't think tcpd is the culprit.

saned not only needs the sane port (6566) but also a port for data
transmission which is selected by the server's operating system. See
man saned. That's not very firewall-friendly.

So you'll have to edit your harden scripts to not block all the user
ports. I'm not sure if this approach of a personal firewall makes sense
at all, but that's another discussion.

Bye,
  Henning