From: "Peter Müller" <peter.mueller@link38.eu>
To: development@lists.ipfire.org
Subject: [PATCH v4 1/3] Unbound: Enable DNS cache poisoning mitigation
Date: Mon, 10 Sep 2018 16:21:24 +0200 [thread overview]
Message-ID: <20180910142126.5265-1-peter.mueller@link38.eu> (raw)
[-- Attachment #1: Type: text/plain, Size: 1117 bytes --]
By default, Unbound neither keeps track of the number of unwanted
replies nor initiates countermeasures if they become too large (DNS
cache poisoning).
This sets the maximum number of tolerated unwanted replies to
1M, causing the cache to be flushed afterwards. (Upstream documentation
recommends 10M as a threshold, but this turned out to be ineffective
against attacks in the wild.)
See https://nlnetlabs.nl/documentation/unbound/unbound.conf/ for
details. This version of the patch uses 1M as threshold instead of
5M and supersedes the first and second version.
Signed-off-by: Peter Müller <peter.mueller(a)link38.eu>
---
config/unbound/unbound.conf | 3 +++
1 file changed, 3 insertions(+)
diff --git a/config/unbound/unbound.conf b/config/unbound/unbound.conf
index 3f724d8f7..ce9ddcd62 100644
--- a/config/unbound/unbound.conf
+++ b/config/unbound/unbound.conf
@@ -61,6 +61,9 @@ server:
harden-algo-downgrade: no
use-caps-for-id: no
+ # Harden against DNS cache poisoning
+ unwanted-reply-threshold: 1000000
+
# Listen on all interfaces
interface-automatic: yes
interface: 0.0.0.0
--
2.16.4
next reply other threads:[~2018-09-10 14:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-10 14:21 Peter Müller [this message]
2018-09-10 14:21 ` [PATCH v4 2/3] Unbound: Use caps for IDs Peter Müller
2018-09-10 14:21 ` [PATCH v4 3/3] Unbound: Use aggressive NSEC Peter Müller
2018-09-10 15:35 ` [PATCH v4 1/3] Unbound: Enable DNS cache poisoning mitigation Michael Tremer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180910142126.5265-1-peter.mueller@link38.eu \
--to=peter.mueller@link38.eu \
--cc=development@lists.ipfire.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox