From: logcabin@fastmail.net
To: wireguard@lists.zx2c4.com
Subject: Re: PostUp/PreUp/PostDown/PreDown Dangerous?
Date: Thu, 21 Jun 2018 21:55:35 -0400 [thread overview]
Message-ID: <1529632535.19086.1416445888.7A63B9D9@webmail.messagingengine.com> (raw)
In-Reply-To: <CAHmME9p6wS7BfWaa-0yHY-+T=ujqWVu_akkc1=XFO_rGAerY7A@mail.gmail.com>
I'm in favor of keeping the features. A competent sysadmin or netadmin should know not to put questionable material on their systems, or at the very least, try it on a test bed where it can't do any damage.
On Thu, Jun 21, 2018, at 9:41 PM, Jason A. Donenfeld wrote:
> Hey list,
>
> wg(8) is the main WireGuard configuration tool. It takes a fairly
> strict set of inputs, and is supposed to perform acceptable input
> validation on them.
>
> https://git.zx2c4.com/WireGuard/about/src/tools/man/wg.8
>
> wg-quick(8), on the other and, is a dinky bash script, that is useful
> for making some common limited use cases a bit easier.
>
> https://git.zx2c4.com/WireGuard/about/src/tools/man/wg-quick.8
>
> wg-quick(8) has the very handy feature of allowing
> PostUp/PostDown/PreUp/PreDown directives, to execute some helpers,
> such as iptables or whatever else you want in a custom setup. These
> have proven very useful to folks. And because these allow arbitrary
> execution anyway, wg-quick(8) doesn't try very hard to do proper input
> validation either.
>
> I just saw this nice post pointing out a problem in OpenVPN:
> https://medium.com/tenable-techblog/reverse-shell-from-an-openvpn-configuration-file-73fd8b1d38da
>
> The same thing applies to wg-quick(8) with
> PostUp/PostDown/PreUp/PreDown. The question is how seriously we should
> take the problem presented by this blog post. Namely, you can't trust
> configuration files given to you by outside parties. Maybe you
> shouldn't reconfigure your network without inspecting what those
> reconfigurations are first. However, one could argue that code
> execution is a bit beyond networking config.
>
> So, the question we need to ask is whether this problem is important
> enough that these useful features should be _removed_? Or if there's a
> way to make them safer? Or if it just doesn't matter that much and we
> shouldn't do anything.
>
> Thoughts?
>
> Jason
> _______________________________________________
> WireGuard mailing list
> WireGuard@lists.zx2c4.com
> https://lists.zx2c4.com/mailman/listinfo/wireguard
next prev parent reply other threads:[~2018-06-22 1:50 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-22 1:34 Jason A. Donenfeld
2018-06-22 1:35 ` Jason A. Donenfeld
2018-06-22 1:41 ` Jason A. Donenfeld
2018-06-22 1:55 ` logcabin [this message]
2018-06-22 1:56 ` Antonio Quartulli
2018-06-22 10:46 ` Jordan Glover
2018-06-22 10:53 ` Antonio Quartulli
2018-06-22 13:08 ` Jacob Baines
2018-06-22 14:47 ` Andy Dorman
2018-06-22 15:14 ` Matthias Urlichs
2018-06-22 17:11 ` Jason A. Donenfeld
2018-06-22 4:01 ` Matthias Urlichs
2018-06-22 5:44 ` Reto Brunner
2018-06-22 14:07 ` Andy Dorman
2018-06-23 19:16 ` Reto Brunner
2018-06-22 19:26 ` Lonnie Abelbeck
2018-06-22 22:13 ` Jordan Glover
2018-06-23 2:36 ` Antonio Quartulli
2018-06-23 7:02 ` Dario Bosch
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