HOMEVULNERABILITIESCVE-2023-4236
HIGH

CVE-2023-4236

CWE-617Published: September 20, 2023· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2023-4236 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

Debian1 product(s)
debian linux
Fedora1 product(s)
fedora
isc1 product(s)
bind
netapp10 product(s)
h300s firmwareh300sh500s firmwareh500sh700s firmwareh700sh410s firmwareh410sh410c firmwareh410c
Source: NVD CPE · 18 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttp://www.openwall.com/lists/oss-security/2023/09/20/2
ADVISORYhttps://kb.isc.org/docs/cve-2023-4236
ADVISORYhttps://lists.fedoraproject.org/archives/list/[email protected]/message/VSK5V4W4OHPM3JTJGWAQD6CZW7SFD75B/
ADVISORYhttps://security.netapp.com/advisory/ntap-20231013-0004/
ADVISORYhttps://www.debian.org/security/2023/dsa-5504
ADVISORYhttp://www.openwall.com/lists/oss-security/2023/09/20/2
ADVISORYhttps://kb.isc.org/docs/cve-2023-4236
ADVISORYhttps://lists.fedoraproject.org/archives/list/[email protected]/message/VSK5V4W4OHPM3JTJGWAQD6CZW7SFD75B/
ADVISORYhttps://security.netapp.com/advisory/ntap-20231013-0004/
ADVISORYhttps://www.debian.org/security/2023/dsa-5504

All References (14)

→
http://www.openwall.com/lists/oss-security/2023/09/20/2Mailing List · Third Party Advisory
→
https://kb.isc.org/docs/cve-2023-4236Vendor Advisory
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/IPJLLTJCSDJJII7IIZPLTBQNWP7MZH7F/Mailing List
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/U35OARLQCPMVCBBPHWBXY5M6XJLD2TZ5/Mailing List
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/VSK5V4W4OHPM3JTJGWAQD6CZW7SFD75B/Mailing List · Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20231013-0004/Third Party Advisory
→
https://www.debian.org/security/2023/dsa-5504Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2023/09/20/2Mailing List · Third Party Advisory
→
https://kb.isc.org/docs/cve-2023-4236Vendor Advisory
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/IPJLLTJCSDJJII7IIZPLTBQNWP7MZH7F/Mailing List
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/U35OARLQCPMVCBBPHWBXY5M6XJLD2TZ5/Mailing List
→
https://lists.fedoraproject.org/archives/list/[email protected]/message/VSK5V4W4OHPM3JTJGWAQD6CZW7SFD75B/Mailing List · Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20231013-0004/Third Party Advisory
→
https://www.debian.org/security/2023/dsa-5504Third Party Advisory

Quick Facts

CVE IDCVE-2023-4236
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-617
CISA KEVNo
Affected4 vendor(s)
PublishedSep 20, 2023

Related CVEs (CWE-617)

CVE-2020-3615
9.8
CVE-2019-9795
9.8
CVE-2020-12417
8.8
CVE-2020-6623
8.8
CVE-2020-6619
8.8
CVE-2020-6617
8.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2023-4236 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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