Improper input validation bug in DNS resolver component of Knot Resolver before 2.4.1 allows remote attacker to poison cache.

published 2018-08-02 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-2974

cvss: 7.5; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 3.2%; EPSS 3.2% chance of exploitation in 30 days, percentile 88%
public exploits: 0; none known

Patch / fix

fixed in 1 distros 1

nic knot_resolver 2.4.1

knot-resolver Debian 14, Debian 13, Debian 12 2.4.1-1

debian advisories DEBIAN-CVE-2018-10920

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-2018-10920 updated 2025-11-21 cvss 7.5

knot-resolver: Improper input validation bug in DNS resolver component

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

3.24% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	7.5	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD	3.1	6.8	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected products

cz.nic knot-resolver

Classification

Weakness

CWE-20 Improper Input Validation

References

knot-resolver.cz /2018-08-02-knot-resolver-2.4.1.html
vendor-advisory
bugzilla.redhat.com /show_bug.cgi?id=CVE-2018-10920
issue-tracking, third-party-advisory

Sources

CVE List CVE-2018-10920
NVD CVE-2018-10920

Fencer Vulns 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.

Summary