Skip to content
Fencer Intel
medium 6.3

CVE-2019-10191 json

A vulnerability was discovered in DNS resolver of knot resolver before version 4.1.0 which allows remote attackers to downgrade DNSSEC-secu…

published 2019-07-16 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-2214

cvss
6.3
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

A vulnerability was discovered in DNS resolver of knot resolver before version 4.1.0 which allows remote attackers to downgrade DNSSEC-secure domains to DNSSEC-insecure state, opening possibility of domain hijack using attacks against insecure DNS protocol.

Patch / fix

  • nic knot_resolver 4.1.0
  • knot-resolver Debian 14, Debian 13, Debian 12 5.0.1-1

debian advisories DEBIAN-CVE-2019-10191

  • knot-resolver Ubuntu 20.04 LTS 3.2.1-3ubuntu2.2

ubuntu advisories UBUNTU-CVE-2019-10191

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • knot-resolver Alpine 3.24, Alpine 3.23, Alpine 3.22 +11 more 4.1.0-r0

alpine advisories ALPINE-CVE-2019-10191

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2019-10191 updated cvss 6.3

knot-resolver: improper input validation in DNS resolver allows remote attacker to poison cache by unsigned negative answer

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.93% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.0 6.3 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • CZ.NIC knot-resolver

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.