Vulnerability Monitor

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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. This is triggered by random subdomains in the NSDNAME in NS records.

Published

2020-05-19T13:15:11.763

Last Modified

2024-11-21T05:00:01.607

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.5 (HIGH)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:N/I:N/A:P

Access Vector: NETWORK
Access Complexity: LOW
Authentication: NONE
Confidentiality Impact: NONE
Integrity Impact: NONE
Availability Impact: PARTIAL

Exploitability Score

10.0

Impact Score

2.9

Weaknesses

Type: Primary
CWE-400
Type: Secondary
CWE-400

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	nic	knot_resolver	< 5.1.1	Yes

References

http://cyber-security-group.cs.tau.ac.il/# Technical Description, Third Party Advisory ([email protected])
http://www.openwall.com/lists/oss-security/2020/05/19/2 Mailing List, Third Party Advisory ([email protected])
https://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/ Technical Description, Vendor Advisory ([email protected])
https://lists.debian.org/debian-lts-announce/2024/04/msg00017.html ([email protected])
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/76Y4FITMOH6RVPWAANGV7NB2ZHPJJGDQ/ ([email protected])
https://www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html Release Notes, Vendor Advisory ([email protected])
http://cyber-security-group.cs.tau.ac.il/# Technical Description, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
http://www.openwall.com/lists/oss-security/2020/05/19/2 Mailing List, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/ Technical Description, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://lists.debian.org/debian-lts-announce/2024/04/msg00017.html (af854a3a-2127-422b-91ae-364da2661108)
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/76Y4FITMOH6RVPWAANGV7NB2ZHPJJGDQ/ (af854a3a-2127-422b-91ae-364da2661108)
https://www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html Release Notes, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)