[Owasp-leaders] Zone transfer

Laurence Casey larry.casey at owasp.org
Fri Apr 9 13:38:28 EDT 2010


I agree entirely on the reason for not allowing zone transfers. BUT..
Allowing them in itself is not a "Security Risk". It is how people use DNS
that becomes the risk. Just a blanket statement of not allowing them is no
justification for considering a site insecure. 

 

Agree, not knowing of a compromise is irrelevant. Rephrase- What compromise
would have occurred? Nothing sensitive has ever been in our DNS. And as long
as I am in control of the DNS records, nothing will ever be. I can guarantee
that.

 

All that and, if it were my DNS servers, I would not allow it just so people
can't tell me this same information. I'm still not seeing the vulnerability
here, but I would be happy to take up Ralph's offer for a DNS server that
does not allow zone transfers.

 

--Larry

 

From: owasp-leaders-bounces at lists.owasp.org
[mailto:owasp-leaders-bounces at lists.owasp.org] On Behalf Of Peter Perfetti
Sent: Friday, April 09, 2010 12:59 PM
To: owasp-leaders at lists.owasp.org
Subject: Re: [Owasp-leaders] Zone transfer

 

My $.02:

Zone transfers are restricted to prevent unauthorized disclosure of internal
machines and network enumeration. 

The fact that no one knows of a past compromise is irrelevant. It is a
potential point of exploitation. Just because you don't know about a past
breach doesn't mean it hasn't occurred.

Perhaps there is nothing sensitive in there now, but can anyone guarantee
that no sensitive information will ever be present?

If a service provider "feels" then perhaps they're not "thinking".
Restricting zone transfers is considered "best practice" for a reason. I
usually include DNS in risk assessments and pen tests, and try to exploit
them and whatever information I find whenever possible.

There is also the reputational aspect that a security-centric organization
does not follow network and system best security practice when we preach our
own standards.

I'd be happy to weigh in more on service provider criteria and oversight if
anyone wishes.

-
Pete


-
Peter Perfetti
Chapter Leader
NY/NJ Metro Chapter
OWASP
peter.perfetti at owasp.org
-



On Fri, Apr 9, 2010 at 9:18 AM, Laurence Casey <larry.casey at owasp.org>
wrote:

Ralph,

 

I have tried working with my current DNS provider on this issue without
success. They feel this is not a security risk. The risk is when people use
DNS for security reasons. As you can see yourself if you do a zone transfer
that nothing is private or used for security. You also mention zone
transfers without authentication? Who should be granted this authenticated
access? If I had security related information in our records, I would
certainly questions everything about OWASP's infrastructure. I use a third
party DNS provider who happens to also be a major hosting company and has
nothing to do with our servers. Also note, that I have been using this same
DNS provider for 10+ years. In those 10+ years, how many times has OWASP
been attacked using this zone transfer? What exploits have been the result? 

 

If somebody on the forum would like to offer a DNS server that does not
allow zone transfers, I will be more than happy to transfer all the OWASP
domain names to them.

 

--Larry

 

From: owasp-leaders-bounces at lists.owasp.org
[mailto:owasp-leaders-bounces at lists.owasp.org] On Behalf Of Ralph Durkee
Sent: Thursday, April 08, 2010 9:03 AM
To: owasp-leaders at lists.owasp.org
Subject: Re: [Owasp-leaders] Zone transfer

 

It doesn't make sense for OWASP to use a DNS server that allows zone
transfers without authentication. This is one of the basics in terms of DNS
security.
It's not the kind of open that should be OWASP.   If the name servers fail
in this are there other issues?  We shouldn't we ask about the security and
then get permission for a test? Most of what we do depends on DNS being
trusted.  

-- Ralph Durkee, CISSP, GSEC, GCIH, GSNA, GPEN
Rochester OWASP
 



Rory McCune wrote: 

On Thu, Apr 8, 2010 at 9:49 AM, OWASP Geneva Chapter
 <mailto:antonio.fontes at owasp.org> <antonio.fontes at owasp.org> wrote:
  

On 8 April 2010 09:00, Erlend Oftedal  <mailto:Erlend.Oftedal at bekk.no>
<Erlend.Oftedal at bekk.no> wrote:
    

Hi
I see this message popping up from time to time on twitter, that owasp.org
is vulnerable to zone transfer.
I guess that's something we want to fix.
"RT @maxisoler: +1 WTF?! RT: @Jabra: Wtf owasp.org is still vulnerable to
zone transfer!"
Erlend
      

Hi Leaders,
 
The initial security requirement dictates that zone content disclosure
should be restricted in order to reduce the risk of hidden/internal
hosts disclosure (which we could even argue it's a "security by
obfuscation" practice).
 
Keeping it open might also mean we did our work correctly, applied
basic risk assessment, and stick to our "openness" principle.
 
(okay okay, devil's advocate now heading towards the exit door)
 
Antonio
 
    

I'd agree in that there shouldn't be "private" information available
in public DNS as there are other ways (eg, DNS brute-force) to get
access to that kind of information.
 
That said, from a PR perspective, it may not look good for us to have
something present in our security posture which is generally
considered a "bad thing", so probably worth changing...
 
my 0.02 of local currency.
 
cheers
 
Rory
_______________________________________________
OWASP-Leaders mailing list
OWASP-Leaders at lists.owasp.org
https://lists.owasp.org/mailman/listinfo/owasp-leaders
 
  


_______________________________________________
OWASP-Leaders mailing list
OWASP-Leaders at lists.owasp.org
https://lists.owasp.org/mailman/listinfo/owasp-leaders

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://lists.owasp.org/pipermail/owasp-leaders/attachments/20100409/41f60b62/attachment.html 


More information about the OWASP-Leaders mailing list