Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| ISC | BIND 9 | 9.16.33 – ≤ 9.16.41, 9.18.7 – ≤ 9.18.15, 9.16.33-S1 – ≤ 9.16.41-S1, 9.18.11-S1 – ≤ 9.18.15-S1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | bind9 | 1:9.18.16-1 | — |
| Debian 13 | bind9 | 1:9.18.16-1 | — |
| Debian 12 | bind9 | 1:9.18.16-1~deb12u1 | DSA-5439-1 |
| Debian 11 | bind9 | 1:9.16.42-1~deb11u1 | DSA-5439-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | bind9 | 1:9.18.12-0ubuntu0.22.04.2 | USN-6183-1 |
| Ubuntu 20.04 LTS | bind9 | 1:9.16.1-0ubuntu2.15 | USN-6183-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP5 | bind | 9.16.42-150500.8.3.1 | SUSE-SU-2023:2836-1 |
| SLES 15 SP4 | bind | 9.16.42-150400.5.27.1 | SUSE-SU-2023:2667-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | bind | 9.18.16-1.1 | openSUSE-SU-2024:13015-1 |
| openSUSE Leap 15.5 | bind | 9.16.42-150500.8.3.1 | SUSE-SU-2023:2836-1 |
| openSUSE Leap 15.4 | bind | 9.16.42-150400.5.27.1 | SUSE-SU-2023:2667-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.15 | bind | 9.16.42-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | bind +17 | 32:9.16.42-1.amzn2023.0.1 | ALAS2023-2023-240 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | bind | 9.16.44-1 | — |
Advisories 8
- WID-SEC-2023-2917 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jun 30, 2026
- USN-6183-1 bind9 vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-5439-1 bind9 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2023:2667-1 Security update for bind SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:2836-1 Security update for bind SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:13015-1 bind-9.18.16-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2023-1533 Internet Systems Consortium BIND: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Jan 6, 2026
- ALAS2023-2023-240 Important: bind security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 20, 2023
References
- CVE-2023-2911 vendor-advisory
- http://www.openwall.com/lists/oss-security/2023/06/21/6
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U3K6AJK7RRSR53HRF5GGKPA6PDUDWOD2/
- https://www.debian.org/security/2023/dsa-5439
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SEFCEVCTYEMKTWA7V7EYPI5YQQ4JWDLI/
- https://security.netapp.com/advisory/ntap-20230703-0010/