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Fencer Vulns
high 7.5

CVE-2023-2911 json

Exceeding the recursive-clients quota may cause named to terminate unexpectedly when stale-answer-client-timeout is set to 0

published 2023-06-21 3 y ago modified 2026-10-24 15 d ago also EUVD-2023-34357

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.4%
EPSS 2.4% chance of exploitation in 30 days, percentile 84%
public exploits
0
none known

Summary

If the `recursive-clients` quota is reached on a BIND 9 resolver configured with both `stale-answer-enable yes;` and `stale-answer-client-timeout 0;`, a sequence of serve-stale-related lookups could cause `named` to loop and terminate unexpectedly due to a stack overflow. This issue affects BIND 9 versions 9.16.33 through 9.16.41, 9.18.7 through 9.18.15, 9.16.33-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1.

Patch / fix

  • bind9 Debian 12 1:9.18.16-1~deb12u1
  • bind9 Debian 14, Debian 13 1:9.18.16-1

debian advisories DEBIAN-CVE-2023-2911

  • bind9 Ubuntu 20.04 LTS 1:9.16.1-0ubuntu2.15
  • bind9 Ubuntu 22.04 LTS 1:9.18.12-0ubuntu0.22.04.2

ubuntu advisories UBUNTU-CVE-2023-2911

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • bind SLE Module for Server Applications 15 SP5, SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 9.16.42-150500.8.3.1
  • bind SLE Module for Server Applications 15 SP4, SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 9.16.42-150400.5.27.1

suse advisories SUSE-SU-2023:2836-1SUSE-SU-2023:2667-1

  • bind openSUSE Tumbleweed 9.18.16-1.1

opensuse advisories openSUSE-SU-2024:13015-1

  • bind Alpine 3.15 9.16.42-r0

alpine advisories ALPINE-CVE-2023-2911

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • bind CBL-Mariner 2.0 9.16.44-1

azure linux advisories AZL-27237

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-2911 updated cvss 7.5

bind: Exceeding the recursive-clients quota may cause named to terminate unexpectedly when stale-answer-client-timeout is set to 0

  • Red Hat Enterprise Linux 6 bind, bind-sdb, bind-libs, bind-utils, bind-chroot Red Hat Enterprise Linux 7 bind, bind-sdb, bind-libs, bind-utils, bind-chroot, bind-pkcs11, +6 more Red Hat Enterprise Linux 8 bind, bind-sdb, bind9.16, bind-libs, bind-utils, bind-chroot, +14 more Red Hat Enterprise Linux 9 bind, dhcp, bind-libs, bind-utils, dhcp-relay, bind-chroot, +6 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
23 mo ago

Exploit prediction

2.43% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • ISC BIND 9

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.