Insufficient verification that responses belong to a query
NLnet Labs ldns 1.2.0 up to and including versions 1.9.0, when used in applications as (stub) resolver over UDP, lacks matching the query destination address and port with the response source address and port. Furthermore not the query ID, neither the question of the query is matched with that of the response. This makes applications, that use ldns for (stub) resolver functionality over UDP, vulnerable for off-path poisoning attacks. The drill tool, which is shipped with ldns, suffers from this vulnerability.
Problem Types
| Type | CWE ID | Description |
|---|
| CWE | CWE-346 | CWE-346 Origin Validation Error |
Type: CWE
Description: CWE-346 Origin Validation Error
Metrics
| Version | Base score | Base severity | Vector |
|---|
| 4.0 | 8.2 | HIGH | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N |
Version: 4.0
Base score: 8.2
Base severity: HIGH
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Timeline
| Event | Date |
|---|
| Issue reported by Pablo Ruiz | 2026-05-14 00:00:00 |
| NLnet Labs shares patch | 2026-06-02 00:00:00 |
| Pablo Ruiz verifies patch | 2026-06-02 00:00:00 |
| Fix released with version 1.9.2 | 2026-06-10 00:00:00 |
Event: Issue reported by Pablo Ruiz
Date: 2026-05-14 00:00:00
Event: NLnet Labs shares patch
Date: 2026-06-02 00:00:00
Event: Pablo Ruiz verifies patch
Date: 2026-06-02 00:00:00
Event: Fix released with version 1.9.2
Date: 2026-06-10 00:00:00