Описание
CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the transfer plugin can select the wrong ACL stanza when both a parent zone and a more-specific subzone are configured. The longestMatch() function in plugin/transfer/transfer.go uses a lexicographic string comparison instead of an actual longest-suffix match to select the winning zone. As a result, a permissive parent-zone transfer rule can override a restrictive subzone rule depending on zone name ordering (e.g., "example.org." > "a.example.org." lexicographically). This allows an unauthorized remote client to perform AXFR/IXFR for the subzone and retrieve its full zone contents. This issue has been fixed in version 1.14.3.
A flaw was found in CoreDNS. An unauthorized remote client can exploit a vulnerability in the transfer plugin's Access Control List (ACL) stanza selection. This occurs when both a parent zone and a more-specific subzone are configured, and the longestMatch() function incorrectly uses a lexicographic string comparison. As a result, a permissive parent-zone transfer rule can override a restrictive subzone rule, allowing the client to perform zone transfers (AXFR/IXFR) for the subzone and retrieve its full zone contents. This leads to the disclosure of sensitive information.
Меры по смягчению последствий
To mitigate this vulnerability, ensure that the CoreDNS transfer plugin is configured with explicit and precise Access Control List (ACL) rules for all zones and subzones. Avoid broad parent-zone transfer rules that could inadvertently override more restrictive subzone configurations. If zone transfers are not required, disable the transfer plugin or restrict its access to only trusted internal networks using firewall rules or CoreDNS configuration directives. Always review and validate transfer plugin configurations to prevent unintended information disclosure.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Advanced Cluster Management for Kubernetes 2 | rhacm2/lighthouse-agent-rhel9 | Fix deferred | ||
| Red Hat Advanced Cluster Management for Kubernetes 2 | rhacm2/lighthouse-coredns-rhel9 | Fix deferred | ||
| Red Hat OpenShift Container Platform 4 | openshift4/ose-coredns-rhel9 | Fix deferred |
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Дополнительная информация
Статус:
EPSS
6.5 Medium
CVSS3
Связанные уязвимости
CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the transfer plugin can select the wrong ACL stanza when both a parent zone and a more-specific subzone are configured. The longestMatch() function in plugin/transfer/transfer.go uses a lexicographic string comparison instead of an actual longest-suffix match to select the winning zone. As a result, a permissive parent-zone transfer rule can override a restrictive subzone rule depending on zone name ordering (e.g., "example.org." > "a.example.org." lexicographically). This allows an unauthorized remote client to perform AXFR/IXFR for the subzone and retrieve its full zone contents. This issue has been fixed in version 1.14.3.
CoreDNS transfer plugin subzone ACL bypass via lexicographic zone comparison
CoreDNS is a DNS server that chains plugins. In versions prior to 1.14 ...
CoreDNS' transfer stanza selection uses lexicographic compare (subzone ACL bypass)
EPSS
6.5 Medium
CVSS3