| Name | CVE-2020-12667 |
| Description | Knot Resolver before 5.1.1 allows traffic amplification via a crafted DNS answer from an attacker-controlled server, aka an "NXNSAttack" issue. This is triggered by random subdomains in the NSDNAME in NS records. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-3795-1 |
| Debian Bugs | 961076 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| knot-resolver (PTS) | buster (security), buster, buster (lts) | 3.2.1-3+deb10u2 | fixed |
| bullseye | 5.3.1-1+deb11u1 | fixed |
| bookworm (security), bookworm | 5.6.0-1+deb12u1 | fixed |
| sid, trixie | 5.7.4-2 | fixed |
The information below is based on the following data on fixed versions.
Notes
https://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/
commit: https://gitlab.labs.nic.cz/knot/knot-resolver/-/commit/54f05e4d7b2e47c0bdd30b84272fc503cc65304b
commit: https://gitlab.labs.nic.cz/knot/knot-resolver/-/commit/ba7b89db780fe3884b4e90090318e25ee5afb118