Описание
NLnet Labs Unbound 1.19.1 up to and including version 1.25.0 has a vulnerability in the DNSSEC validator that enables denial of service and possible remote code execution as a result of deep copying a data structure and erroneously overwriting a destination pointer. An adversary can exploit the vulnerability by controlling a malicious signed zone and querying a vulnerable Unbound. When DS sub-queries need to suspend validation due to NSEC3 computational budget exhaustion (introduced in Unbound 1.19.1), Unbound deep-copies response messages to preserve them across memory region teardown. A struct-assignment bug overwrites the destination's pointer with the source's pointer. After the sub-query region is freed, the resumed validator dereferences this dangling pointer, triggering a crash or potentially enabling arbitrary code execution. Unbound 1.25.1 contains a patch with a fix to preserve the correct pointer when deep copying the data structure.
A flaw was discovered in Unbound’s DNSSEC validator can leave it using an invalid memory pointer after certain DS sub-query validations fail due to NSEC3 budget exhaustion. This may cause crashes and could potentially allow arbitrary code execution.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | unbound | Out of support scope | ||
| Red Hat Enterprise Linux 7 | unbound | Not affected | ||
| Red Hat Enterprise Linux 8 | unbound | Not affected | ||
| Red Hat OpenShift Container Platform 4 | rhcos | Affected | ||
| Red Hat Enterprise Linux 10 | unbound | Fixed | RHSA-2026:23231 | 04.06.2026 |
| Red Hat Enterprise Linux 9 | unbound | Fixed | RHSA-2026:24369 | 08.06.2026 |
| Red Hat Hardened Images | unbound-main-1.25.1-0.1.hum1 | Fixed | RHSA-2026:19752 | 20.05.2026 |
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Дополнительная информация
Статус:
8.1 High
CVSS3
Связанные уязвимости
NLnet Labs Unbound 1.19.1 up to and including version 1.25.0 has a vulnerability in the DNSSEC validator that enables denial of service and possible remote code execution as a result of deep copying a data structure and erroneously overwriting a destination pointer. An adversary can exploit the vulnerability by controlling a malicious signed zone and querying a vulnerable Unbound. When DS sub-queries need to suspend validation due to NSEC3 computational budget exhaustion (introduced in Unbound 1.19.1), Unbound deep-copies response messages to preserve them across memory region teardown. A struct-assignment bug overwrites the destination's pointer with the source's pointer. After the sub-query region is freed, the resumed validator dereferences this dangling pointer, triggering a crash or potentially enabling arbitrary code execution. Unbound 1.25.1 contains a patch with a fix to preserve the correct pointer when deep copying the data structure.
NLnet Labs Unbound 1.19.1 up to and including version 1.25.0 has a vulnerability in the DNSSEC validator that enables denial of service and possible remote code execution as a result of deep copying a data structure and erroneously overwriting a destination pointer. An adversary can exploit the vulnerability by controlling a malicious signed zone and querying a vulnerable Unbound. When DS sub-queries need to suspend validation due to NSEC3 computational budget exhaustion (introduced in Unbound 1.19.1), Unbound deep-copies response messages to preserve them across memory region teardown. A struct-assignment bug overwrites the destination's pointer with the source's pointer. After the sub-query region is freed, the resumed validator dereferences this dangling pointer, triggering a crash or potentially enabling arbitrary code execution. Unbound 1.25.1 contains a patch with a fix to preserve the correct pointer when deep copying the data structure.
Possible arbitrary code execution during DNSSEC validation
NLnet Labs Unbound 1.19.1 up to and including version 1.25.0 has a vul ...
8.1 High
CVSS3