CVE-2023-4236
named may terminate unexpectedly under high DNS-over-TLS query load
A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load.
This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
named may terminate unexpectedly under high DNS-over-TLS query load
A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load.
This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
- Record
CVE-2023-4236- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
EUVDEUVD-2023-54109
A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load.
This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
- Record
EUVD-2023-54109- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-jhh4-vhhc-xpjq
A flaw in the networking code handling DNS-over-TLS queries may cause `named` to terminate...
A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load.
This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
- Record
GHSA-jhh4-vhhc-xpjq- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-617
- Updated
- 2026-11-02
NVD
A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load.
This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
- Record
CVE-2023-4236- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-617
- Updated
- 2026-11-02
OSVALPINE-CVE-2023-4236
A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load.
This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
- Record
ALPINE-CVE-2023-4236- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVBELL-CVE-2023-4236
- Record
BELL-CVE-2023-4236- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 6 moreShow less
OSV
A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load.
This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
- Record
CVE-2023-4236- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2023-4236
A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load. This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
- Record
DEBIAN-CVE-2023-4236- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2023-4236
A flaw in the networking code handling DNS-over-TLS queries may cause named to terminate unexpectedly due to an assertion failure. This happens when internal data structures are incorrectly reused under significant DNS-over-TLS query load. This issue affects BIND 9 versions 9.18.0 through 9.18.18 and 9.18.11-S1 through 9.18.18-S1.
- Record
UBUNTU-CVE-2023-4236- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVMGASA-2023-0303 No score
Updated bind packages fix security vulnerabilities
The code that processes control channel messages sent to named calls
certain functions recursively during packet parsing. Recursion depth is
only limited by the maximum accepted packet size; depending on the
environment, this may cause the packet-parsing code to run out of
available stack memory, causing named to terminate unexpectedly. Since
each incoming control channel message is fully parsed before its
contents are authenticated, exploiting this flaw does not require the
attacker to hold a valid RNDC key; only network access to the control
channel's configured TCP port is necessary. (CVE-2023-3341)
A flaw in the networking code handling DNS-over-TLS queries may cause
named to terminate unexpectedly due to an assertion failure. This
happens when internal data structures are incorrectly reused under
significant DNS-over-TLS query load. (CVE-2023-4236)
- Record
MGASA-2023-0303- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:13249-1 No score
bind-9.18.19-1.1 on GA media
These are all security issues fixed in the bind-9.18.19-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:13249-1- Updated
- 2026-11-02
OSVUSN-6390-1 No score
bind9 vulnerabilities
It was discovered that Bind incorrectly handled certain control channel messages. A remote attacker with access to the control channel could possibly use this issue to cause Bind to crash, resulting in a denial of service. (CVE-2023-3341)
Robert Story discovered that Bind incorrectly handled certain DNS-over-TLS queries. A remote attacker could possibly use this issue to cause Bind to crash, resulting in a denial of service. This issue only affected Ubuntu 22.04 LTS, and Ubuntu 23.04. (CVE-2023-4236)
- Record
USN-6390-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
bindAlpine:v3.17 |
9.18.0 up to 9.18.19-r0 | 9.18.19-r0 |
bindAlpine:v3.18 |
9.18.0 up to 9.18.19-r0 | 9.18.19-r0 |
bindAlpine:v3.19 |
9.18.0 up to 9.18.19-r0 | 9.18.19-r0 |
bindAlpine:v3.20 |
9.18.0 up to 9.18.19-r0 | 9.18.19-r0 |
bindAlpine:v3.21 |
9.18.0 up to 9.18.19-r0 | 9.18.19-r0 |
bindAlpine:v3.22 |
9.18.0 up to 9.18.19-r0 | 9.18.19-r0 |
bindAlpine:v3.23 |
9.18.0 up to 9.18.19-r0 | 9.18.19-r0 |
bindAlpine:v3.24 |
9.18.0 up to 9.18.19-r0 | 9.18.19-r0 |
bindAlpaquita:23 |
9.18.11-r0 up to 9.18.19-r0 | 9.18.19-r0 |
bind9Debian:12 |
before 1:9.18.19-1~deb12u1, plus listed versions 1:9.18.12-11:9.18.13-11:9.18.16-11:9.18.16-1~deb12u11:9.18.16-1~deb12u1~bpo11+11:9.18.19-1~deb12u1~bpo11+1 |
1:9.18.19-1~deb12u1 |
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| Package | Affected | Fixed |
|---|---|---|
bind9Debian:13 |
before 1:9.19.17-1 | 1:9.19.17-1 |
bind9Debian:14 |
before 1:9.19.17-1 | 1:9.19.17-1 |
bindMageia:9 From an advisory covering 2 CVEs |
before 9.18.15-2.2.mga9 | 9.18.15-2.2.mga9 |
bind9Ubuntu:22.04:LTS |
before 1:9.18.12-0ubuntu0.22.04.3, plus listed versions 1:9.16.15-1ubuntu11:9.16.15-1ubuntu21:9.16.15-1ubuntu31:9.18.0-2ubuntu11:9.18.0-2ubuntu2 Show 7 moreShow less1:9.18.0-2ubuntu31:9.18.1-1ubuntu11:9.18.1-1ubuntu1.11:9.18.1-1ubuntu1.21:9.18.1-1ubuntu1.31:9.18.12-0ubuntu0.22.04.11:9.18.12-0ubuntu0.22.04.2 |
1:9.18.12-0ubuntu0.22.04.3 |
bind9Ubuntu:24.04:LTS |
before 1:9.18.18-0ubuntu2 | 1:9.18.18-0ubuntu2 |
bind9Ubuntu:20.04:LTS From an advisory covering 2 CVEs |
before 1:9.16.1-0ubuntu2.16, plus listed versions 1:9.11.5.P4+dfsg-5.1ubuntu21:9.11.5.P4+dfsg-5.1ubuntu31:9.11.5.P4+dfsg-5.1ubuntu41:9.11.5.P4+dfsg-5.1ubuntu51:9.11.14+dfsg-1ubuntu1 Show 19 moreShow less1:9.11.14+dfsg-3ubuntu11:9.16.0-1ubuntu31:9.16.0-1ubuntu41:9.16.0-1ubuntu51:9.16.1-0ubuntu11:9.16.1-0ubuntu21:9.16.1-0ubuntu2.11:9.16.1-0ubuntu2.21:9.16.1-0ubuntu2.31:9.16.1-0ubuntu2.41:9.16.1-0ubuntu2.61:9.16.1-0ubuntu2.71:9.16.1-0ubuntu2.81:9.16.1-0ubuntu2.91:9.16.1-0ubuntu2.101:9.16.1-0ubuntu2.111:9.16.1-0ubuntu2.121:9.16.1-0ubuntu2.141:9.16.1-0ubuntu2.15 |
1:9.16.1-0ubuntu2.16 |
bind9Ubuntu:22.04:LTS From an advisory covering 2 CVEs |
before 1:9.18.12-0ubuntu0.22.04.3, plus listed versions 1:9.16.15-1ubuntu11:9.16.15-1ubuntu21:9.16.15-1ubuntu31:9.18.0-2ubuntu11:9.18.0-2ubuntu2 Show 7 moreShow less1:9.18.0-2ubuntu31:9.18.1-1ubuntu11:9.18.1-1ubuntu1.11:9.18.1-1ubuntu1.21:9.18.1-1ubuntu1.31:9.18.12-0ubuntu0.22.04.11:9.18.12-0ubuntu0.22.04.2 |
1:9.18.12-0ubuntu0.22.04.3 |
bindopenSUSE:Tumbleweed From an advisory covering 2 CVEs |
before 9.18.19-1.1 | 9.18.19-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-4236 is a high vulnerability (CVSS 7.5) in Isc Bind, published September 20, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.19%, the 82nd percentile. Fixed in bind 9.18.19-r0.
References
kb.isc.org/docs/cve-2023-4236
openwall.com/lists/oss-security/2023/09/20/2
debian.org/security/2023/dsa-5504
lists.fedoraproject.org/archives/list/[email protected]/message/IPJLLTJCSDJJII7IIZPLTBQNWP7MZH7F
security.netapp.com/advisory/ntap-20231013-0004
Show 14 moreShow less
nvd.nist.gov/vuln/detail/CVE-2023-4236
github.com/advisories/GHSA-jhh4-vhhc-xpjq
security.alpinelinux.org/vuln/CVE-2023-4236
docs.bell-sw.com/security/cves/CVE-2023-4236
security-tracker.debian.org/tracker/CVE-2023-4236
advisories.mageia.org/MGASA-2023-0303.html
bugs.mageia.org/show_bug.cgi?id=32039
ubuntu.com/security/notices/USN-6390-1
cve.org/CVERecord?id=CVE-2023-4236
suse.com/security/cve/CVE-2023-3341