knot-resolver before version 4.3.0 is vulnerable to denial of service through high CPU utilization
Published Dec 16, 2019
7.5
HIGHCVSS 3.1
EPSS 2.17%
Description
knot-resolver before version 4.3.0 is vulnerable to denial of service through high CPU utilization. DNS replies with very many resource records might be processed very inefficiently, in extreme cases taking even several CPU seconds for each such uncached message. For example, a few thousand A records can be squashed into one DNS message (limit is 64kB).
Affected products
-
- Version 4.3.0StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Cz.nic | Knot-Resolver | n/a |
|
Configuration 1
- < 4.3.0
Configuration 2
- 10.0
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:L/Au:N/C:N/I:N/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v5
Table of values (14 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 2.17% (0.02166) | 81.58th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.17% (0.02166) | 79.82th | v5 (v2026.06.15) |
| Jul 20, 2024 | 0.24% (0.00245) | 64.96th | v3 (v2023.03.01) |
| Apr 26, 2024 | 0.24% (0.00245) | 64.15th | v3 (v2023.03.01) |
| Apr 10, 2024 | 0.11% (0.00109) | 43.09th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.15% (0.00155) | 49.92th | v3 (v2023.03.01) |
| Mar 6, 2023 | 0.89% (0.00885) | 27.89th | v2 (v2022.01.01) |
| Sep 10, 2022 | 0.89% (0.00885) | 26.24th | v2 (v2022.01.01) |
| Apr 1, 2022 | 0.89% (0.00885) | 24.24th | v2 (v2022.01.01) |
| Feb 4, 2022 | 4.50% (0.04499) | 74.08th | v2 (v2022.01.01) |
| Feb 3, 2022 | 3.40% (0.03396) | 67.40th | v1 |
| Jan 6, 2022 | 3.40% (0.03396) | 67.08th | v1 |
| Sep 1, 2021 | 0.78% (0.00777) | 50.67th | v1 |
| Apr 14, 2021 | 0.78% (0.00777) | 0.00th | v1 |
References (3)
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-19331 ExploitIssue TrackingPatch
- https://lists.debian.org/debian-lts-announce/2024/04/msg00017.html mailing-list
- https://www.knot-resolver.cz/2019-12-04-knot-resolver-4.3.0.html Release NotesVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-19331 | ExploitIssue TrackingPatch | |
| https://lists.debian.org/debian-lts-announce/2024/04/msg00017.html | mailing-list | |
| https://www.knot-resolver.cz/2019-12-04-knot-resolver-4.3.0.html | Release NotesVendor Advisory |
Change history (0)
No recorded changes yet.