Описание
A use-after-return vulnerability exists in the named server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure.
This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1.
BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.
A flaw was found in BIND, specifically in the named server's handling of DNS queries signed with SIG(0). A remote attacker could exploit this use-after-return vulnerability by sending a specially-crafted DNS request. This could cause an Access Control List (ACL) to improperly match an IP address, potentially leading to unauthorized access to resources.
Отчет
This vulnerability has a Moderate impact. A use-after-return flaw in the named server of bind9 allows a remote attacker to send a specially-crafted DNS request signed with SIG(0). This can lead to improper Access Control List (ACL) matching, potentially granting unauthorized access to resources. Red Hat Enterprise Linux 8 and 9 ship with BIND versions 9.16 and 9.18 respectively, which are not affected by this flaw. Red Hat Enterprise Linux 10 is affected.
Меры по смягчению последствий
Restrict network access to the named service to trusted clients and networks. Configure firewall rules to limit inbound connections to the DNS service port (UDP/TCP 53). For example, using firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_IP_RANGE>" port port="53" protocol="udp" accept' and firewall-cmd --reload. This action may impact DNS resolution for clients outside the specified trusted networks. A service reload or restart may be required for changes to take effect.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | bind | Fix deferred | ||
| Red Hat Enterprise Linux 6 | bind | Not affected | ||
| Red Hat Enterprise Linux 7 | bind | Not affected | ||
| Red Hat Enterprise Linux 8 | bind | Not affected | ||
| Red Hat Enterprise Linux 8 | bind9.16 | Not affected | ||
| Red Hat Enterprise Linux 9 | bind | Not affected | ||
| Red Hat Enterprise Linux 9 | bind9.18 | Not affected | ||
| Red Hat Enterprise Linux 9 | dhcp | Not affected | ||
| Red Hat OpenShift Container Platform 4 | rhcos | Not affected | ||
| Red Hat Hardened Images | bind-main-9.18.48-1.hum1 | Fixed | RHSA-2026:6935 | 07.04.2026 |
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Дополнительная информация
Статус:
EPSS
5.4 Medium
CVSS3
Связанные уязвимости
A use-after-return vulnerability exists in the `named` server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.
A use-after-return vulnerability exists in the `named` server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.
A stack use-after-return flaw in SIG(0) handling code may enable ACL bypass
A use-after-return vulnerability exists in the `named` server when han ...
A use-after-return vulnerability exists in the `named` server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.
EPSS
5.4 Medium
CVSS3