DNS Attacks

Robert Bonomi bonomi at mail.r-bonomi.com
Sun Feb 19 10:14:45 CST 2012


> From ken.gilmour at gmail.com  Sun Feb 19 05:04:39 2012
> Date: Sun, 19 Feb 2012 11:59:37 +0100
> Subject: Re: DNS Attacks
> From: Ken Gilmour <ken.gilmour at gmail.com>
> To: Robert Bonomi <bonomi at mail.r-bonomi.com>
> Cc: nanog at nanog.org
>
> On Feb 18, 2012 10:24 PM, "Robert Bonomi" <bonomi at mail.r-bonomi.com> wrote:
> >
> > Even better, nat to a 'bogon' DNS server -- one that -- regardless of the
> > query -- returns the address of a dedicated machine on your network set up
> > especially for this purpose.
>
> What happens when the client sends a POST from a cached page on the end
> user's machine? E.g. if they post login credentials. Of course, they'll get
> the error page, but then you have confidential data in your logs and now
> you have to protect highly confidential info, at least if you're in europe.
>

*WHAT* 'confidential data' in which logs?   <grin>

The aforementioned dedicated machine isn't a real web-server, or a real
'any other' server -- it is solely a special-purpose application machine,
When you connect to it on say, port 80, it doesn't log anything from the 
port -- it just logs (1) the timestamp, and (2) the connecting IP address 
(and _nothing_ else); then it copies out a previously prepared static file,
and disconnects.

You build a separae app that reads that logfile, matches IP ddress/timestamp
to a customer account, and feeds a message into the 'customer records' system
that this customer -has- been notified of this problem, and when, in case 
they call for support.

If one is 'really' paranoid, the 'logfile' can be implemented as a 'pipe'
between the processes, so that the data never hits disk in the first place. ;)

I've got proof-of-concept code for a single program that handles HTTP (port
80), SMTP (port 25 and port 587), POP3 (port 110), IMAP2 & 4 (port 143), IMAP3
(port 220), TELNET (port 23), FTP (port 21), and NNTP (port 119), so far.   
I'm planing to add IRC, and various SSL-based protocols as well.





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