Remote UDP DoS by sending multiple DNS Cookie options (NLnet Labs NSD)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.46 % · percentile 40 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- NLnet Labs
- NVD status
- Analyzed
Description
Any remote client can crash a (debugging/non-release build type) NSD serve child by sending it a special crafted message with a specially tuned number of DNS Cookie options (17 when UDP payload size is 512). By continuously crashing the serve childs, the remote client can severely hamper or, when positioned sufficiently close, deny all DNS service.
Weaknesses (CWE)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | HIGH 8.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | NLnet Labs |
| CVSS 4.0 | HIGH 8.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · sep@nlnetlabs.nl (Secondary) |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-66349
- GCVE · GCVE-0-2026-19401
Affected configurations (NVD CPE)
cpe:2.3:a:nlnetlabs:nsd:*:*:*:*:*:*:*:*≥ 4.3.7 < 4.15.1
Affected products
| Product | Versions |
|---|---|
| NLnet Labs · NSD | affected 4.3.7 < 4.15.1 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |