zeroconf and security

[Harald Hoyer]

With all those DHCP and DNS magic, the question comes up, if there is any security check
involved?
Will the user be asked, if he accepts the configuration from DHCP server x which gives
additional DNS server y, which pulls in several configurations?

Without security checks I could redirect a users desktop easily to my linux laptop, which
maybe answers a DHCP request faster than the company DHCP server.

Just my concerns.

Harald

[Colin Walters]

On Tue, 2004-08-24 at 12:54 +0200, Harald Hoyer wrote:
>  With all those DHCP and DNS magic, the question comes up, if there is
> any security check involved?
>  Will the user be asked, if he accepts the configuration from DHCP server x which gives
> additional DNS server y, which pulls in several configurations?
>  
>  Without security checks I could redirect a users desktop easily to my linux laptop,
>  which maybe answers a DHCP request faster than the company DHCP server. 
Sure.  You can also answer DNS requests faster than the company DNS
server.  There's nothing new here, these protocols are insecure. Barring
widespread use of DNSSEC, security has to come at a higher level via
IPSec, TLS, etc.

[Harald Hoyer]

Colin Walters wrote:
>  On Tue, 2004-08-24 at 12:54 +0200, Harald Hoyer wrote:
>  
> >With all those DHCP and DNS magic, the question comes up, if there is any security
> check involved?
> >Will the user be asked, if he accepts the configuration from DHCP server x which gives
> additional DNS server y, which pulls in several configurations?
> >
> >Without security checks I could redirect a users desktop easily to my linux laptop,
> >which maybe answers a DHCP request faster than the company DHCP server.
>  
>  
>  Sure.  You can also answer DNS requests faster than the company DNS
>  server.  There's nothing new here, these protocols are insecure. Barring
>  widespread use of DNSSEC, security has to come at a higher level via
>  IPSec, TLS, etc. 
DNS or DHCP?

[Sean Middleditch]

On Tue, 2004-08-24 at 15:23 +0200, Harald Hoyer wrote:
>  Colin Walters wrote:
>  > Sure.  You can also answer DNS requests faster than the company DNS
>  > server.  There's nothing new here, these protocols are insecure. Barring
>  > widespread use of DNSSEC, security has to come at a higher level via
>  > IPSec, TLS, etc.
>  
>  DNS or DHCP? 
Both.  They both have the exact same potential problems.  Actually,
*any* protocol has this problem, unless it has some sort of
authentication method.  I can easily put up a web server on the local
net that answers for the same IP as the corporate web server.  If the
connection isn't encrypted or the clients ignore certificate warnings, I
can attack your network with very little effort once I'm inside.

>  
>   
-- 
Sean Middleditch <elanthis(a)awesomeplay.com&gt;
AwesomePlay Productions, Inc.

[Alan Cox]

On Tue, Aug 24, 2004 at 12:54:35PM +0200, Harald Hoyer wrote:
>  With all those DHCP and DNS magic, the question comes up, if there is
> any 
>  security check involved?
>  Will the user be asked, if he accepts the configuration from DHCP server x 
>  which gives additional DNS server y, which pulls in several configurations? 
Someone may also want to review the script that runs when we get a dhcp
reply. I can given a hostile dhcp server make it do funky things but not
break it