Am 04.09.2015 um 20:41 schrieb Leandro:
I think that regarding security issues, is better to prevent as much as possible. Here we have two different opinions: People that agree to use firewall and people against (or arguing that is not necessary): I would like to hear both and then decide. If we share our points maybe can get a better conclusions So I would like to learn about firewall techniques to protect a DNS. And for people against firewall , wich are the security considerations to take in order to protect the service without firewall.
AFAIR nobody said anything against firewalls in general, but the "multiple firewalls in a row" is just nonsense and don't improve security in a deterministic way
but it brings more points of failure and in the worst case more vulnerable points in case of one or more of that firewalls are outdated and vulerable itself - commercial "security appliances" are famous for all sort of outdated software where a simple security audit shows you more vulerabilities on that crap than in your whole network (Barracuda Networks as example)
what you need is *one* firewall you trustif you don't trust it and that is the only valid reason to build up a cascade of firewalls put it out of your network
mostly people who are throwing as much as possible appliances and firewalls in front of their machines doing that because missing knowledge and hope some of the stuff they are throwing in the mix will magically catch whatever - that's not how security really works, you need to understand what you are installing and doing, throwing as much as possible things in the mix just leads that you no longer understand what your own network really does, but that don't bother attackers shooting blindly with all sorts of expolits in the hope one hits
well, and that attackers are shooting directly to your firewalls too
On 04/09/15 14:27, Mike Hoskins (michoski) wrote:On 9/4/15, 1:12 PM, "bind-users-boun...@lists.isc.org on behalf of /dev/rob0" <bind-users-boun...@lists.isc.org on behalf of r...@gmx.co.uk> wrote:On Thu, Sep 03, 2015 at 11:02:23PM +0200, Reindl Harald wrote:Am 03.09.2015 um 22:59 schrieb Robert Moskowitz:On 09/03/2015 04:35 PM, Leandro wrote:Ok ... I got BIND 9.10.2-P3 working. I compiled with ./configure --with-openssl --enable-threads --with-libxml2 --with-libjson make make install Json statistics channel is working and chroot is not longer mandatory.But do make sure you have selinux enforced. Or run behind multiple firewalls...behind *multiple firewalls* - ?!?! - oh come on and get serious instead promote snakeoil -I quite agree here. Firewalls that attempt to filter DNS have terrible reputations for *breaking* DNS. A single firewall is bad enough; multiple firewalls sounds like a disaster.True, have fixed many of those over the years, though in fairness this is often a matter of expecting to run a firewall (or anything) "out of box" without understanding the config. If that's the stance of the admin, you likely have a lot more to worry about security-wise than named chroot. :-)typically BIND is *not* running as root and hence does not need any special handling compared to any other network serviceI don't know if we can say what is "typical". We can say, for running on Linux at least, that running as root is safe. A compromised named would get root after having dropped superuser privileges, so it wouldn't be able to do much.I probably misunderstand your response or am reading too much into the wording. Named doesn't run as root due to -u giving up permissions. That combined with the fact chroot itself has known shortcomings is why it's fallen out of BCP amongst name server operators. It's not that anyone suggests the alternative to chroot is to just run as root. You are still running as a non-privileged user post-startup, and permissioning things appropriately to minimize damage in the event of a compromise.Regardless, again I quite agree that special handling is not necessary. Look at the various BIND9 security announcements over the years. When have you seen one which involved a compromise of any kind? I cannot say with authority that BIND9 has never had a compromise, but I am confident in saying I have never seen one.I appreciate the viewpoint, and I can even agree with it, but the past is not necessarily a key to the future. The reality is none of the nastiest 0-days were ever expected. As a security professional you try to insulate against potential risks, not just things you have already observed. It's up to each operator to determine appropriate cost/benefit, and this is not an argument for chroot, but I do caution against an "I've never seen it before so wouldn't worry about it" stance on security.
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