[ale] Is Promiscuous Sniffing just not so much Fun anymore? (mostly on-topic)

dev null oh two dev.null.02 at gmail.com
Tue Dec 10 20:09:59 EST 2013


what if I compromised a host on the same switch as the servers and used 
ARP spoofing or overflowed the CAM table, or any other number of L2 
attacks to then sniff your unencrypted data?

I have compromised many lower "importance" hosts and then pivoted inward 
and pcapped $sensitive_data because admins don't understand the idea of 
layered defense.

PCI is generally bullshit, but on this point, your auditor is right.

and if you're going to implement TLS between the servers, please, use PFS.

On 12/10/2013 7:45 PM, Brian Mathis wrote:
> If the local switch was compromised and placed into monitor mode, then 
> a 3rd party could sniff the traffic, but now you're talking some 
> really specific case.  It's generally considered secure to have one 
> server talk to another over a local switch, otherwise things like NFS 
> and databases would be a huge pain, if not impossible to use.
>
> However, which do you consider more of a threat?  The overhead of 
> switching to HTTPS, or an auditor who fails you on an audit?  Maybe 
> you would pick the former, but I'm sure your business would pick the 
> latter.  Keeping auditors happy is just as important as "real" work.
>
>
> ? Brian Mathis
>
>
> On Tue, Dec 10, 2013 at 5:42 PM, Neal Rhodes <neal at mnopltd.com 
> <mailto:neal at mnopltd.com>> wrote:
>
>     I hear that.   But two servers, same rack, plugged into the same
>     switch, on the same LAN, will not hit their gateway router - they
>     will ARP to find each other, and talk through the switch, and you
>     ain't gonna see any of that, even if you managed to plug into the
>     data center switch.  Correct?
>
>     We're playing a little devil's advocate here, trying to decide if
>     we're looking at securing against a realistic threat or just
>     keeping the auditors happy.
>
>     On Tue, 2013-12-10 at 17:02 -0500, JD wrote:
>>     If 2 locations are connected through public internet, don't trust it. There are
>>     routing attacks which have been known for years and I suspect any 2 sites using
>>     HTTP or HTTPS connections in that way will be unlikely to be monitoring network
>>     performance at much detail.
>>
>>     Servers should be on a different subnet and fire walled from desktops even in
>>     the same location.
>>
>>     Can't recall where I saw a recent article about this, but routing has both
>>     accidentally and with clear purpose caused traffic to be sent very far away from
>>     expected places.  Recall when all youtube traffic was sent through Pakistan
>>     "accidentally"? I am positive that could be done between two corporate locations
>>     using the internet for connections too.
>>
>>     IPSec. Not sure I'd trust anything less.
>>
>>     On 12/10/2013 02:08 PM, Neal Rhodes wrote:
>>     > So, picture two servers which talk to each other within a corporate LAN/WAN in a
>>     > data center, and worker bees in an office location elsewhere in the same city,
>>     > who only have hard-wired LAN access, and assume they have IP connectivity to the
>>     > data center.
>>     >
>>     > And picture that these two servers have an unsecured http protocol they talk over.
>>     >
>>     > And picture a worker bee with too much time on their hands and the intent to
>>     > hijack this.
>>     >
>>     > If said worker bee managed to get WireShark or similar installed on their
>>     > workstation,  they could sniff whatever that hard Cat5 cable can see.    Which,
>>     > assuming it is connected to a switch, not an old-fashioned hub, is pretty much
>>     > zilch.   Basically their own traffic.
>>     >
>>     > They can't see most traffic to/from the guy in the next cubicle to the servers,
>>     > because the switch doesn't normally let them see it.   For performance reasons,
>>     > it isolates each LAN port.    They can't see any of the server-server packets,
>>     > because the two routers in between behave like switches, not hubs, and don't
>>     > route local server-server traffic.
>>     >
>>     > So, assuming that Wifi is not available, it seems like the LAN sniffer attack
>>     > vector based on seeing what is happening is pretty much moot.    That is not to
>>     > say that actively probing isn't rewarding.
>>     >
>>     > Let's take it one step farther: presume that it is trivial for these two servers
>>     > to switch from talking http:80 to each other and start talking https:443 to each
>>     > other.    From the perspective above, this is a negligible practical
>>     > improvement.    It only gets interesting if we imagine someone able to get onto
>>     > the local LAN in the data center.  But even then, presuming that is also a
>>     > switch, they ain't gonna see spit.
>>     >
>>     > Let's take it one step farther: assume that they could in fact compromise the
>>     > data center switch, and capture a pile of the https traffic between servers.
>>     > Would we logically assume that given today's technology that they could manage
>>     > to decrypt it with enough CPU and time?
>>     >
>>     > Thoughts?
>>     >
>>     > Neal Rhodes
>>     > MNOP Ltd
>>     >
>>     >
>>     _______________________________________________
>>     Ale mailing list
>>     Ale at ale.org  <mailto:Ale at ale.org>
>>     http://mail.ale.org/mailman/listinfo/ale
>>     See JOBS, ANNOUNCE and SCHOOLS lists at
>>     http://mail.ale.org/mailman/listinfo
>
>
>     _______________________________________________
>     Ale mailing list
>     Ale at ale.org <mailto:Ale at ale.org>
>     http://mail.ale.org/mailman/listinfo/ale
>     See JOBS, ANNOUNCE and SCHOOLS lists at
>     http://mail.ale.org/mailman/listinfo
>
>
>
>
> _______________________________________________
> Ale mailing list
> Ale at ale.org
> http://mail.ale.org/mailman/listinfo/ale
> See JOBS, ANNOUNCE and SCHOOLS lists at
> http://mail.ale.org/mailman/listinfo

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ale.org/pipermail/ale/attachments/20131210/3a30163f/attachment.html>


More information about the Ale mailing list