{"id":"CVE-2020-12667","details":"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.","modified":"2026-07-08T16:26:43.387526Z","published":"2020-05-19T13:15:11.763Z","references":[{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2024/04/msg00017.html"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/76Y4FITMOH6RVPWAANGV7NB2ZHPJJGDQ/"},{"type":"ADVISORY","url":"http://cyber-security-group.cs.tau.ac.il/#"},{"type":"ADVISORY","url":"http://www.openwall.com/lists/oss-security/2020/05/19/2"},{"type":"ADVISORY","url":"https://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/"},{"type":"ADVISORY","url":"https://www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/cz-nic/knot-resolver","events":[{"introduced":"0"},{"fixed":"24f5932a12484446bb9e88a52c6c36cfa6cb1afe"}],"database_specific":{"cpe":"cpe:2.3:a:nic:knot_resolver:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"5.1.1"}],"source":"CPE_RANGE"}}],"versions":["v5.1.0","v5.0.1","v5.0.0","v4.3.0","v4.2.2","v4.2.0","v4.1.0","v4.0.0","v3.2.1","v3.2.0","v3.1.0","v3.0.0","v2.4.0","v2.3.0","v2.2.0","v2.1.1","v2.1.0","v2.0.0","v1.5.1","v1.5.0","v1.4.0","v1.3.3","v1.3.2","v1.3.1","v1.3.0","v1.2.6","v1.2.1","v1.2.0","v1.2.0-rc3","v1.2.0-rc2","v1.2.0-rc1","v1.1.1","v1.1.0","v1.0.0","v1.0.0-beta3","v1.0.0-beta2","v1.0.0-beta1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-12667.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}