High severity · published May 19, 2020
CVE-2020-12667
Knot Resolver before 5.1.1 allows traffic amplification via a crafted DNS answer from an attacker-controlled server, aka an "NXNSAttack" issue
7.5
CVSS
2.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)2.6% · higher than 85% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KR
Knot Resolver · Nic
before 5.1.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-12667
CVE.org
https://www.cve.org/CVERecord?id=CVE-2020-12667
Technical Description
http://cyber-security-group.cs.tau.ac.il/#
Mailing List
http://www.openwall.com/lists/oss-security/2020/05/19/2
Technical Description
https://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/
lists.debian.org
https://lists.debian.org/debian-lts-announce/2024/04/msg00017.html
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/76Y4FITMOH6RVPWAANGV7NB2ZHPJJGDQ/
Release Notes
https://www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html
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