CVE-2022-40188
CVE-2022-40188 is a high-severity vulnerability in Nic Knot Resolver with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-407.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 2% (72nd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-407
- Affected product: Nic Knot Resolver
- Published:
- Last modified:
Description
Knot Resolver before 5.5.3 allows remote attackers to cause a denial of service (CPU consumption) because of algorithmic complexity. During an attack, an authoritative server must return large NS sets or address sets.
Frequently asked questions
- What is CVE-2022-40188?
- Knot Resolver before 5.5.3 allows remote attackers to cause a denial of service (CPU consumption) because of algorithmic complexity. During an attack, an authoritative server must return large NS sets or address sets.
- How severe is CVE-2022-40188?
- CVE-2022-40188 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2022-40188 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2022-40188?
- CVE-2022-40188 primarily affects Nic Knot Resolver. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2022-40188?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2022-40188 published?
- CVE-2022-40188 was published on 2022-09-23 and last updated on 2026-06-17.
References
- https://gitlab.nic.cz/knot/knot-resolver/-/merge_requests/1343#note_262558
- https://lists.debian.org/debian-lts-announce/2022/10/msg00008.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HIMDNIUI7GTUEKIBBYYW7OCTJQFPDNXL/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/S2VE5K3VDUHJOIA2IGT3G5R76IBADMNE/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XO6LIVQS62MI5GG4OVYB5RHVZMYNHAHG/
Affected products (5)
- cpe:2.3:a:nic:knot_resolver:*:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
More vulnerabilities in Nic Knot Resolver
- CVE-2023-50387 — High (CVSS 7.5): Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to…
- CVE-2023-46317 — High (CVSS 7.5): Knot Resolver before 5.7.0 performs many TCP reconnections upon receiving certain nonsensical responses from servers.
- CVE-2023-26249 — High (CVSS 7.5): Knot Resolver before 5.6.0 enables attackers to consume its resources, launching amplification attacks and potentially…
- CVE-2021-40083 — High (CVSS 7.5): Knot Resolver before 5.3.2 is prone to an assertion failure, triggerable by a remote attacker in an edge case (NSEC3…
- CVE-2018-1110 — High (CVSS 7.5): A flaw was found in knot-resolver before version 2.3.0. Malformed DNS messages may cause denial of service.
- CVE-2020-12667 — High (CVSS 7.5): Knot Resolver before 5.1.1 allows traffic amplification via a crafted DNS answer from an attacker-controlled server,…
All CVEs affecting Nic Knot Resolver →
Other CWE-407 vulnerabilities
- CVE-2026-58226 — High (CVSS 8.7): Inefficient Algorithmic Complexity vulnerability in elixir-mint hpax allows unauthenticated denial-of-service via…
- CVE-2026-54892 — High (CVSS 8.7): Inefficient algorithmic complexity in Plug's nested-parameter decoder allows an unauthenticated remote attacker to…
- CVE-2026-59094 — High (CVSS 7.5): Pathway through 0.31.1, fixed in commit d09722e, document store applies a caller-supplied glob pattern to indexed…
- CVE-2026-53433 — High (CVSS 7.5): fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to…
- CVE-2026-13311 — High (CVSS 7.5): shell-quote prior to 1.8.5 finalizes parsed tokens in parse() using Array.prototype.concat as a reduce accumulator,…
- CVE-2026-48516 — High (CVSS 7.5): MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7,…