Описание
NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data structures for the options. Coordinated attacks can result in degradation and/or denial of service. Unbound 1.25.1 contains a patch with a fix to limit acceptable incoming EDNS options (100).
A flaw was found in Unbound. A remote attacker can exploit this vulnerability by sending queries with an excessive number of EDNS (Extension Mechanisms for DNS) options. This can cause Unbound threads to be held hostage while parsing and creating internal data structures for these options. Coordinated attacks can lead to resource exhaustion, resulting in a degradation of service or a denial of service (DoS) for legitimate users.
Отчет
A flaw of Important severity was found in Unbound, the validating recursive DNS resolver shipped in Red Hat Enterprise Linux and included in other Red Hat products such as Red Hat OpenShift Container Platform and Red Hat In-Vehicle OS. A remote attacker requiring no privileges or user interaction can send DNS queries containing an excessive number of EDNS (Extension Mechanisms for DNS) options, which can hold Unbound worker threads hostage while they parse the options and create internal data structures for them. Coordinated attacks of this kind can exhaust server resources, resulting in degradation of service or denial of service for legitimate users; confidentiality and integrity are not affected. The Red Hat severity of Important (CVSS:3.1 score of 7.5, AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) is consistent with the NIST and upstream CVSS:3.1 scores, although the upstream CVSS:4.0 base score is lower (6.6, Moderate). Only product streams that ship the affected unbound component are impacted; several streams have been assessed as not affected in current triage. Fixes for the affected streams are being pursued by the responsible component maintainers.
Меры по смягчению последствий
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure. Until patched, restrict the resolver to authorized client networks via firewall and apply DNS rate limiting per source IP. Service watchdog and cgroup limits provide resilience but are not a substitute for patching.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Data Grid 8 | unboundid-ldapsdk | Not affected | ||
| Red Hat Enterprise Linux 6 | unbound | Affected | ||
| Red Hat Enterprise Linux 7 | unbound | Affected | ||
| Red Hat JBoss Enterprise Application Platform Expansion Pack | unboundid-ldapsdk | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Affected | ||
| Red Hat OpenShift Container Platform 5 | openshift/ose-rhel-coreos-9 | Affected | ||
| Red Hat OpenStack Platform 16.2 | rhosp-rhel8-tech-preview/openstack-unbound | Affected | ||
| Red Hat OpenStack Platform 17.1 | rhosp-rhel9/openstack-unbound | Affected | ||
| Red Hat OpenStack Platform 18.0 | rhoso/openstack-unbound-rhel9 | Affected | ||
| Red Hat OpenStack Platform 18.0 | rhoso-operators/designate-rhel9-operator | Not affected |
Показывать по
Дополнительная информация
Статус:
EPSS
7.5 High
CVSS3
Связанные уязвимости
NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data structures for the options. Coordinated attacks can result in degradation and/or denial of service. Unbound 1.25.1 contains a patch with a fix to limit acceptable incoming EDNS options (100).
NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to a degradation of service attack related to parsing long lists of incoming EDNS options. An adversary sending queries with too many EDNS options can hold Unbound threads hostage while they are parsing and creating internal data structures for the options. Coordinated attacks can result in degradation and/or denial of service. Unbound 1.25.1 contains a patch with a fix to limit acceptable incoming EDNS options (100).
NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to ...
EPSS
7.5 High
CVSS3