Логотип exploitDog
Консоль
Логотип exploitDog

exploitDog

ubuntu логотип

CVE-2026-55717

Опубликовано: 22 июл. 2026
Источник: ubuntu
Приоритет: medium
CVSS3: 5.9

Описание

In NLnet Labs Unbound 1.10.0 up to and including 1.25.1, when 'serve-expired: yes' is set together with a 'response-ip: redirect' /'response-ip-data: CNAME ' rule (or the RPZ 'rpz-cname-override' equivalent), a remote client who controls any delegated domain can crash the daemon. The serve-expired-client-timeout callback runs a two-pass loop to chase the respip-generated CNAME alias; on the second pass it resets 'alias_rrset' but not 'partial_rep'. Later, this inconsistency leads to a NULL pointer dereference and an eventual crash. A malicious actor can exploit the vulnerability by controlling any zone that replies with an A/AAAA record that falls inside the configured response-ip/rpz subnet. By delaying the answer when the previous record has expired, the vulnerable path of 'serve-expired-client-timeout' is taken leading to denial of service via the server crash.

РелизСтатусПримечание
devel

needs-triage

esm-infra-legacy/trusty

needs-triage

esm-infra-legacy/xenial

needs-triage

esm-infra/bionic

needs-triage

esm-infra/focal

needs-triage

jammy

needs-triage

noble

needs-triage

resolute

needs-triage

upstream

released

1.25.2-1

Показывать по

5.9 Medium

CVSS3

Связанные уязвимости

CVSS3: 5.9
nvd
11 дней назад

In NLnet Labs Unbound 1.10.0 up to and including 1.25.1, when 'serve-expired: yes' is set together with a 'response-ip: <net> redirect' /'response-ip-data: <net> CNAME <target>' rule (or the RPZ 'rpz-cname-override' equivalent), a remote client who controls any delegated domain can crash the daemon. The serve-expired-client-timeout callback runs a two-pass loop to chase the respip-generated CNAME alias; on the second pass it resets 'alias_rrset' but not 'partial_rep'. Later, this inconsistency leads to a NULL pointer dereference and an eventual crash. A malicious actor can exploit the vulnerability by controlling any zone that replies with an A/AAAA record that falls inside the configured response-ip/rpz subnet. By delaying the answer when the previous record has expired, the vulnerable path of 'serve-expired-client-timeout' is taken leading to denial of service via the server crash.

CVSS3: 5.9
msrc
11 дней назад

'serve-expired-client-timeout' and 'response-ip' CNAME redirect could lead to a crash

CVSS3: 5.9
debian
11 дней назад

In NLnet Labs Unbound 1.10.0 up to and including 1.25.1, when 'serve-e ...

CVSS3: 5.9
github
11 дней назад

In NLnet Labs Unbound 1.10.0 up to and including 1.25.1, when 'serve-expired: yes' is set together with a 'response-ip: <net> redirect' /'response-ip-data: <net> CNAME <target>' rule (or the RPZ 'rpz-cname-override' equivalent), a remote client who controls any delegated domain can crash the daemon. The serve-expired-client-timeout callback runs a two-pass loop to chase the respip-generated CNAME alias; on the second pass it resets 'alias_rrset' but not 'partial_rep'. Later, this inconsistency leads to a NULL pointer dereference and an eventual crash. A malicious actor can exploit the vulnerability by controlling any zone that replies with an A/AAAA record that falls inside the configured response-ip/rpz subnet. By delaying the answer when the previous record has expired, the vulnerable path of 'serve-expired-client-timeout' is taken leading to denial of service via the server crash.

5.9 Medium

CVSS3