Re: wpad.dat attack on Linux Apache server

From	Joe Beanfish <joebeanfish@nospam.duh>
Newsgroups	comp.os.linux.networking, comp.os.linux.security, comp.infosystems.www.servers.unix
Subject	Re: wpad.dat attack on Linux Apache server
Date	2013-05-24 13:39 +0000
Organization	A noiseless patient Spider
Message-ID	<knnqit$ib6$1@dont-email.me> (permalink)
References	(6 earlier) <mr-17CDE1.12235424052013@News.Individual.NET> <knnhma$50u$4@dont-email.me> <mr-011092.14433624052013@News.Individual.NET> <519f6593$0$15954$e4fe514c@news2.news.xs4all.nl> <mr-D7D3D2.15141924052013@News.Individual.NET>

Cross-posted to 3 groups.

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On Fri, 24 May 2013 15:14:19 +0200, Sandman wrote:

> In article <519f6593$0$15954$e4fe514c@news2.news.xs4all.nl>,
>  Casper H.S. Dik <Casper.Dik@OrSPaMcle.COM> wrote:
> 
>> >Yes, I have seen this thread, and they are talking about wildcard DNS
>> >being the culprit - I have yet to understand how this applies to me?
>> 
>> All systems shipped these days are configured to search for a automatic
>> proxy configuration from "http://wpad/wpad.dat"
> 
> All? I thought it was Windows thing.
> 
>> Because of your use of wildcard DNS *everyone* who starts their
>> webbrowser will find wpad.their.domain then look for it on your
>> webserver.
> 
> Why? I mean - when they go to wpad.their.domain, why would they end up
> with the IP of my server, or the CNAME of cluster.mydomain.com
> 
> That's the part I just can't understand.
> 
>> Your ip filtering rules block your customers; it also makes their web
>> experience interesting (it will take some time before the system
>> figures out that there is no wpad.dat and will then connect to the
>> internet directly)
> 
> But the people surfing to my web server wouldn't be asking my server,
> any more than microsoft.com, for information about their own networks
> proxy settings, surely?
> 
>> >I mean - I *DO* use wildcard DNS for all domains that I have a DNS
>> >for. The DNS server is on the machine that is currently being flooded
>> >on port 80. Ok. So the DNS is "ns1.mydomain.com" (for example).
>> 
>> Well, you shouldn't have done that.
> 
> Fair enough, but I still don't know how that messed this up. I just
> can't wrap my head around it.

Wildcard DNS is asking for issues unless you fully understand all the
ramifications. Best not to use it unless you really really need it and
fully understand it.

You have no entry for "wpad" so your wildcard is used. Get people off your
server by creating a wpad entry in your dns that points to a nonexistent
host or a host you want to handle that discovery traffic, even if only
to reject it.

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Thread

wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 11:22 +0200
  Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-24 10:37 +0100
    Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 11:44 +0200
      Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-24 11:04 +0100
        Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 12:13 +0200
          Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-24 11:20 +0100
            Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 12:23 +0200
              Re: wpad.dat attack on Linux Apache server J G Miller <miller@yoyo.ORG> - 2013-05-24 11:07 +0000
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 14:43 +0200
                Re: wpad.dat attack on Linux Apache server Casper H.S. Dik <Casper.Dik@OrSPaMcle.COM> - 2013-05-24 13:05 +0000
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 15:14 +0200
                Re: wpad.dat attack on Linux Apache server Joe Beanfish <joebeanfish@nospam.duh> - 2013-05-24 13:39 +0000
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 16:23 +0200
                Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-24 15:13 +0100
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 16:26 +0200
                Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-24 17:38 +0100
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 19:02 +0200
                Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-24 18:45 +0100
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 21:12 +0200
                Re: wpad.dat attack on Linux Apache server Casper H.S. Dik <Casper.Dik@OrSPaMcle.COM> - 2013-05-24 16:47 +0000
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 18:53 +0200
                Re: wpad.dat attack on Linux Apache server J G Miller <miller@yoyo.ORG> - 2013-05-24 17:15 +0000
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 21:20 +0200
                Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-25 08:45 +0100
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-25 09:54 +0200
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-25 10:04 +0200
                Re: wpad.dat attack on Linux Apache server Casper H.S. Dik <Casper.Dik@OrSPaMcle.COM> - 2013-05-26 10:12 +0000
                Re: wpad.dat attack on Linux Apache server "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2013-05-24 13:50 -0400
                Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-24 19:10 +0100
                Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-24 19:15 +0100
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 21:33 +0200
                Re: wpad.dat attack on Linux Apache server Richard Kettlewell <rjk@greenend.org.uk> - 2013-05-25 08:38 +0100
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 21:25 +0200
                Re: wpad.dat attack on Linux Apache server Whiskers <catwheezel@operamail.com> - 2013-05-25 15:52 +0100
                Re: wpad.dat attack on Linux Apache server Roger <invalid@invalid.invalid> - 2013-05-25 17:19 +0100
                Re: wpad.dat attack on Linux Apache server J G Miller <miller@yoyo.ORG> - 2013-05-25 17:22 +0000
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-25 19:41 +0200
              Re: wpad.dat attack on Linux Apache server Chris Davies <chris-usenet@roaima.co.uk> - 2013-05-24 12:31 +0100
                Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 14:29 +0200
                Re: wpad.dat attack on Linux Apache server Chris Davies <chris-usenet@roaima.co.uk> - 2013-05-24 23:45 +0100
  Re: wpad.dat attack on Linux Apache server Sandman <mr@sandman.net> - 2013-05-24 14:49 +0200

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