Описание
To trigger the issue, three configuration parameters must have specific settings: "hostname-char-set" must be left at the default setting, which is "[^A-Za-z0-9.-]"; "hostname-char-replacement" must be empty (the default); and "ddns-qualifying-suffix" must NOT be empty (the default is empty). DDNS updates do not need to be enabled for this issue to manifest. A client that sends certain option content would then cause kea-dhcp4 to exit unexpectedly.
This issue affects Kea versions 3.0.1 through 3.0.1 and 3.1.1 through 3.1.2.
A flaw was found in Kea. A remote attacker can send specific option content to the kea-dhcp4 server. When the server is configured with specific parameters, an assertion failure can be triggered and cause the kea-dhcp4 process to exit unexpectedly, resulting in a denial of service.
Отчет
To exploit this issue, three configuration parameters must have the following settings:
- hostname-char-set: must have the default setting, which is "[^A-Za-z0-9.-]".
- hostname-char-replacement: must be empty, which is the default value.
- ddns-qualifying-suffix: must NOT be empty, which is not the default. A remote and unauthenticated attacker can cause the kea-dhcp4 process to exit unexpectedly by sending specific option content, preventing all DHCP clients it servers from obtaining new leases or renewing existing ones until the service is restarted. Due to this reason, this flaw has been rated with an important severity.
Меры по смягчению последствий
Set the "hostname-char-replacement" parameter to any non-empty value (the default is empty). For example, setting it to "x" is an effective workaround, regardless of other settings.
Дополнительная информация
Статус:
EPSS
7.5 High
CVSS3
Связанные уязвимости
To trigger the issue, three configuration parameters must have specific settings: "hostname-char-set" must be left at the default setting, which is "[^A-Za-z0-9.-]"; "hostname-char-replacement" must be empty (the default); and "ddns-qualifying-suffix" must *NOT* be empty (the default is empty). DDNS updates do not need to be enabled for this issue to manifest. A client that sends certain option content would then cause kea-dhcp4 to exit unexpectedly. This issue affects Kea versions 3.0.1 through 3.0.1 and 3.1.1 through 3.1.2.
To trigger the issue, three configuration parameters must have specific settings: "hostname-char-set" must be left at the default setting, which is "[^A-Za-z0-9.-]"; "hostname-char-replacement" must be empty (the default); and "ddns-qualifying-suffix" must *NOT* be empty (the default is empty). DDNS updates do not need to be enabled for this issue to manifest. A client that sends certain option content would then cause kea-dhcp4 to exit unexpectedly. This issue affects Kea versions 3.0.1 through 3.0.1 and 3.1.1 through 3.1.2.
To trigger the issue, three configuration parameters must have specifi ...
To trigger the issue, three configuration parameters must have specific settings: "hostname-char-set" must be left at the default setting, which is "[^A-Za-z0-9.-]"; "hostname-char-replacement" must be empty (the default); and "ddns-qualifying-suffix" must *NOT* be empty (the default is empty). DDNS updates do not need to be enabled for this issue to manifest. A client that sends certain option content would then cause kea-dhcp4 to exit unexpectedly. This issue affects Kea versions 3.0.1 through 3.0.1 and 3.1.1 through 3.1.2.
EPSS
7.5 High
CVSS3