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.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 1.38% Top 25%
Vendor Advisory fedoraproject.org Vendor Advisory nic.cz Vendor Advisory knot-resolver.cz
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/ technical description vendor advisory
https://www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html release notes vendor advisory
http://www.openwall.com/lists/oss-security/2020/05/19/2 third party advisory mailing list
http://cyber-security-group.cs.tau.ac.il/# third party advisory technical description
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/76Y4FITMOH6RVPWAANGV7NB2ZHPJJGDQ/ vendor advisory
https://lists.debian.org/debian-lts-announce/2024/04/msg00017.html mailing list

Frequently Asked Questions

What is the severity of CVE-2020-12667?
CVE-2020-12667 has been scored as a high severity vulnerability.
How to fix CVE-2020-12667?
To fix CVE-2020-12667, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2020-12667 being actively exploited in the wild?
It is possible that CVE-2020-12667 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.