Who would be the right person to bother about this?
--
Sent from the Delta quadrant using Borg technology!
Nux!
www.nux.ro
----- Original Message -----
From: "Wido den Hollander" <w...@widodh.nl>
To: dev@cloudstack.apache.org
Sent: Monday, 23 June, 2014 12:26:08 PM
Subject: Re: [security] The case of the open dns resolver
On 06/23/2014 12:31 PM, Nux! wrote:
> Hi,
>
> Today I've been bitten again by the $subject and complaints were sent to my
> hoster's abuse email address; apparently someone used my VR in a DDOS attack.
> It is my fault as I knew about this issue, but I'd like to throw the blame on
> Cloudstack. :)
>
> So, the VR is accepting DNS requests from everybody on the interwebs and this
> should be changed, imho.
>
> I see there are already iptables rules concerning port 8080 of the VR and
> only the public IP ranges are allowed. Why isn't this the case for port 53 as
> well?
>
I see no reason why this shouldn't be the case. DNS is only meant for
the Instances and not for the rest of the internet in this case.
> I have placed this script in my VR's rc.local, but it's not kosher at all.
>
> # disallows global DNS traffic and only allows it from the cloud public
> subnets
> for i in `iptables-save |grep 8080|awk '{print $4}'`; do iptables -I INPUT -s
> $i -p tcp -m tcp --dport 53 -j ACCEPT; iptables -I INPUT -s $i -p udp -m udp
> --dport 53 -j ACCEPT; done
> iptables -D INPUT -i eth0 -p udp -m udp --dport 53 -j ACCEPT
> iptables -D INPUT -i eth0 -p tcp -m tcp --dport 53 -j ACCEPT
>
> This could be greatly improved and added in the official tree.
> Currently I'm getting the subnets by checking which IPs the 8080 rules apply,
> how can I retrieve this information in a more elegant way?
>
> Lucian
>
> --
> Sent from the Delta quadrant using Borg technology!
>
> Nux!
> www.nux.ro
>
