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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:May 19, 2020
    Last Modified:Nov 21, 2024
    EPS:May 19, 2020
    EPSS Score:0.00543
    CVSS Score:7.5

    Affected Products

    Vendor
    Nic
    Product
    Knot Resolver

    Exploits

    No exploit reference

    Related CVEs

    CVE-2026-66374 (CVSS 8.1) — Knot Resolver before 6.4.1 allows remote code execution via a heap-based buffer overflow in the DoQ (DNS-over-…
    CVE-2023-50387 (CVSS 7.5) — Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote atta…
    CVE-2023-46317 (CVSS 7.5) — Knot Resolver before 5.7.0 performs many TCP reconnections upon receiving certain nonsensical responses from s…
    CVE-2023-26249 (CVSS 7.5) — Knot Resolver before 5.6.0 enables attackers to consume its resources, launching amplification attacks and pot…
    CVE-2022-40188 (CVSS 7.5) — Knot Resolver before 5.5.3 allows remote attackers to cause a denial of service (CPU consumption) because of a…
    CVE-2022-32983 (CVSS 5.3) — Knot Resolver through 5.5.1 may allow DNS cache poisoning when there is an attempt to limit forwarding actions…
    CVE-2021-40083 (CVSS 7.5) — Knot Resolver before 5.3.2 is prone to an assertion failure, triggerable by a remote attacker in an edge case …
    CVE-2018-1110 (CVSS 7.5) — A flaw was found in knot-resolver before version 2.3.0. Malformed DNS messages may cause denial of service.…
    CVE-2019-19331 (CVSS 7.5) — knot-resolver before version 4.3.0 is vulnerable to denial of service through high CPU utilization. DNS replie…
    CVE-2019-10191 (CVSS 7.5) — A vulnerability was discovered in DNS resolver of knot resolver before version 4.1.0 which allows remote attac…

    References

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

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High