What’s Vulnerable › Vulnerabilities
CVE-2022-40188
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.9% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2022-09-23 · updated 2026-06-17
- Weakness: CWE-407
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.
Affected products
- Debian Linux: 10.0
- Fedoraproject Fedora: 35, 36, 37
- CZ.NIC knot-resolver: before 5.5.3 — fixed in 5.5.3
How to fix
Upgrade to a fixed version: CZ.NIC knot-resolver 5.5.3. Check the vendor advisory for mitigations.
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/
- 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/
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