Vulnerability Development mailing list archives

RE: DNS zone transfer


From: "Brad Bemis" <bradleyb () bigfoot com>
Date: Sun, 9 Jun 2002 10:45:18 -0700

It looks to me as though they are blocking TCP/53 (note UDP/53 is used for
queries and TCP/53 is used for the zone transfer).  There could also be a
split-DNS implementation that hinders your efforts ( restricting the number
and type of records that you might be able to locate on the externally
accessible name server)...  They may also have the DNS tree set up so that
only qualified name servers can conduct zone transfer.  These are all common
best practices when protecting DNS servers.

Have you looked at secondary DNS servers associated with this target?  Many
times, a secondary DNS server is forgotten about...  Since they use the
simple name structure of ns1.wustl.edu, you could script query attempts
against a range of name servers using an nsx loop...   Read in the results
and if they do not match a zone transfer denial (i.e. "*** Can't list domain
domain.com: Query refused"), you have a target...

Just a few ideas...   There are several more advanced methods that could
also be used, but they do not involve passive information gathering ;-)



-----Original Message-----
From: Vlad [mailto:progman () netvision net il]
Sent: Sunday, June 09, 2002 1:02 AM
To: 'Short_Circut'
Cc: vuln-dev () securityfocus com
Subject: RE: DNS zone transfer


First of all thanks for the answer, but I must say that I've already
tried all that.

Using nslookup returns the following:
=====================================
ls -d domain.com
[[ns.domain.com]]
*** Can't list domain domain.com: Query refused

domain.com
domain.com        nameserver = ns.domain.com
....            ....
domain.com
        primary name server = ns1.domain.com
        responsible mail addr = p
        serial  = 1234567890
        refresh = 3600 (1 hour)
        retry   = 600 (10 mins)
        expire  = 86400 (1 day)
        default TTL = 3600 (1 hour)
ns.domain.com    internet address = x.x.x.x
=====================================
The request to enumerate all domain records (first ex.) returns "Query
refused".
A resolve request (second ex.) return what seems like all nameserver
records for that domain (type = ALL in nslookup).

That's nice but not as important as the other records the server
contains , they are the ones I'm after.

Suggestions?


  - Vlad.


-----Original Message-----
From: Short_Circut [mailto:circut () TheSocket remoteserver org]
Sent: Sunday, June 09, 2002 3:22 AM
To: Vlad
Cc: vuln-dev () securityfocus com
Subject: Re: DNS zone transfer




Greetings,

Is it possible to remotely retrieve all DNS records from a server
*without* knowing the specific zones it hosts?
(cause then I can script "dig @dns-server.ip zone-domain ALL" )

If it matters the server runs the DNS service on Win2k and I've got no
preferance for Windows or *NIX tools. Any will do.


Thanks,
 - Vlad.


try 'host' and nslookup.

host -l wustl.edu

and nslookup

[root@TheSocket - <~> nslookup
Default Server:  Server.thesocket.net
Address:  10.0.2.1

server ns1.wustl.edu
Default Server:  ns1.wustl.edu
Address:  128.252.135.4

ls -d wustl.edu


hehehe
view the nice result

:~Short_Circut~:


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