bugtraq - RE: Re: recursive DNS servers DDoS as a growing DDoSproblem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <EKECJMGPAACGOMIGLJJDIEIBGNAA.geoincidents@nls.net>
Date: Wed, 8 Mar 2006 13:27:18 -0500
From: "Geo." <geoincidents@....net>
To: <bugtraq@...urityfocus.com>
Cc: full-disclosure@...ts.grok.org.uk
Subject: RE: Re: recursive DNS servers DDoS as a growing
	DDoSproblem

>>In the scenario you describe, I cannot see any actual amplification...

I'll give you a senario where you can see.

lets say you have 2 name servers that are local to you.

I setup a domain, example.com. In this domain I create a text record which is 100K in length, I don't know, perhaps I paste the source code to decss in it, whatever it's a big text record.

Now I simply spoof a UDP packet using your IP address as the source address and send it to both of your dns servers. This packet is a query for the example.com text record. I have now sent two very small packets and you have received 200K of traffic. That's the amplification, one small udp packet, one large text record in return.

Note, I don't have to use your local servers, but this way it makes it more fun to troubleshoot because it looks like you are the cause of your own flooding..

Geo.

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/