`CVE-2023-34462` Netty

Affected software	Netty
Severity	6.5 Medium CVSS 3.1 2 scores
Fixed in	`4.1.94.Final`
Weakness	Uncontrolled resource consumption (CWE-400)
Published	22 Jun 2023
Updated	17 Jun 2026

Description

Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. The SniHandler can allocate up to 16MB of heap for each channel during the TLS handshake. When the handler or the channel does not have an idle timeout, it can be used to make a TCP server using the SniHandler to allocate 16MB of heap. The SniHandler class is a handler that waits for the TLS handshake to configure a SslHandler according to the indicated server name by the ClientHello record. For this matter it allocates a ByteBuf using the value defined in the ClientHello record. Normally the value of the packet should be smaller than the handshake packet but there are not checks done here and the way the code is written, it is possible to craft a packet that makes the SslClientHelloHandler. This vulnerability has been fixed in version 4.1.94.Final.

CWE-770

Exploitation status

No public exploit

No exploit has been reported in the sources we check. Published 3 years ago.

CISA KEV not listed
VulnCheck KEV not listed
CISA Vulnrichment exploitation: none
Indexed PoC none indexed
EPSS 2.5% chance in 30 days

Waratek protection

No exploit published

Within Waratek scope. In the sources we check, nobody has published exploit code for this CVE or reported it being exploited.

A public code fix exists: netty/netty 535da17.

Protection none
Action unverified
Review automated Upstream data
Record active

Decided by	Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all
Finding	This CVE is not listed in CISA KEV or VulnCheck KEV, CISA Vulnrichment records no active exploitation, no reviewed exploit catalogue carries an entry for it, and no GitHub PoC repository for it has 5 or more stars. Nobody has published exploit code worth tracing, so it is not a candidate for a rule ahead of the ones where somebody has; an upstream fix path does exist, so the remediation half of the candidacy still holds. This is a statement about what has been published, not about whether the defect is reachable or serious.
Candidate fix	https://github.com/netty/netty/commit/535da17e45201ae4278c0479e6162bb4127d4c32 : a commit: the change itself

Decided by

Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

Finding

This CVE is not listed in CISA KEV or VulnCheck KEV, CISA Vulnrichment records no active exploitation, no reviewed exploit catalogue carries an entry for it, and no GitHub PoC repository for it has 5 or more stars. Nobody has published exploit code worth tracing, so it is not a candidate for a rule ahead of the ones where somebody has; an upstream fix path does exist, so the remediation half of the candidacy still holds. This is a statement about what has been published, not about whether the defect is reachable or serious.

Candidate fix

https://github.com/netty/netty/commit/535da17e45201ae4278c0479e6162bb4127d4c32 : a commit: the change itself

CVSS

6.5 MEDIUM v3.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H 2 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

Version Score Band Vector Assigner Type

CVSS 3.1 6.5 MEDIUM CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H security-advisories@github.com Secondary published

CVSS 3.1 6.5 MEDIUM CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H NVD Primary

Version	Score	Band	Vector	Assigner	Type
CVSS 3.1	6.5	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`	security-advisories@github.com	Secondary	published
CVSS 3.1	6.5	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`	NVD	Primary

Affected software and releases

Oracle advisories

Advisory	Type	Quarter	Products Oracle names in its risk matrix
Oracle Critical Patch Update January 2024 ↗	CPU	2024-Q1	Oracle NoSQL Database / Administration (Netty) (Prior to 19.5.40, Prior to 20.3.38, Prior to 21.2.30, Prior to 22.3.94, Prior to 23.1.29) Oracle Utilities Applications / NMS Monitor (Netty) (2.5.0.1, 2.5.0.2, 2.6.0.0)
Oracle Critical Patch Update October 2023 ↗	CPU	2023-Q4	Oracle Analytics / Analytics Server (Netty) (6.4.0.0.0) Oracle Communications / Configuration (Netty) (23.1.3) Oracle Communications / General (Netty) (9.0.0-9.0.2) Oracle Communications / Install/Upgrade (Netty) (23.1.0-23.1.7, 23.2.0-23.2.2) Oracle Communications / Install/Upgrade (Netty) (23.1.0-23.1.8, 23.2.0-23.2.4) Oracle Communications / Platform (Netty) (23.1.3) Oracle Communications / Third Party (Netty) (23.2.0) Oracle Communications Applications / Common fns (Netty) (12.0.6.0) Oracle Communications Applications / Common fns (Netty) (12.0.6.0) Oracle Communications Applications / HTTPGW (Netty) (12.0.0.4-12.0.0.8) Oracle Financial Services Applications / Accessibility (Netty) (14.5-14.7) Oracle Financial Services Applications / Common (Netty) (14.5-14.7) Oracle Financial Services Applications / Common (Netty) (14.5-14.7) Oracle Financial Services Applications / Common Core (Netty) (14.5-14.7) Oracle Financial Services Applications / Dashboard (Netty) (14.5-14.7) Oracle Financial Services Applications / Infrastructure (Netty) (14.5-14.7) Oracle Financial Services Applications / Onboarding Batch Processes (Netty) (14.5-14.7) Oracle Financial Services Applications / Reports (Netty) (14.5-14.7) Oracle Financial Services Applications / Security (Netty) (14.5-14.7) Oracle Financial Services Applications / UI (Netty) (18.3, 19.1, 19.2, 21.1, 22.1, 22.2) Oracle Financial Services Applications / UI (Netty) (2.7) Oracle Financial Services Applications / UI (Netty) (2.7) Oracle Fusion Middleware / Security Framework (Netty) (12.2.1.4.0) Oracle Fusion Middleware / Third Party (Netty) (14.1.1.0.0, 12.2.1.4.0) Oracle PeopleSoft / Elastic Search (Netty) (8.59, 8.60) Oracle TimesTen In-Memory Database / EM TimesTen plug-in (Netty) (Prior to 22.1.1.18.0, Prior to 18.1.4.39.0)

Advisory

Type

Quarter

Products Oracle names in its risk matrix

Oracle Critical Patch Update January 2024 ↗

CPU

2024-Q1

Oracle NoSQL Database / Administration (Netty) (Prior to 19.5.40, Prior to 20.3.38, Prior to 21.2.30, Prior to 22.3.94, Prior to 23.1.29)
Oracle Utilities Applications / NMS Monitor (Netty) (2.5.0.1, 2.5.0.2, 2.6.0.0)

Oracle Critical Patch Update October 2023 ↗

CPU

2023-Q4

Oracle Analytics / Analytics Server (Netty) (6.4.0.0.0)
Oracle Communications / Configuration (Netty) (23.1.3)
Oracle Communications / General (Netty) (9.0.0-9.0.2)
Oracle Communications / Install/Upgrade (Netty) (23.1.0-23.1.7, 23.2.0-23.2.2)
Oracle Communications / Install/Upgrade (Netty) (23.1.0-23.1.8, 23.2.0-23.2.4)
Oracle Communications / Platform (Netty) (23.1.3)
Oracle Communications / Third Party (Netty) (23.2.0)
Oracle Communications Applications / Common fns (Netty) (12.0.6.0)
Oracle Communications Applications / Common fns (Netty) (12.0.6.0)
Oracle Communications Applications / HTTPGW (Netty) (12.0.0.4-12.0.0.8)
Oracle Financial Services Applications / Accessibility (Netty) (14.5-14.7)
Oracle Financial Services Applications / Common (Netty) (14.5-14.7)
Oracle Financial Services Applications / Common (Netty) (14.5-14.7)
Oracle Financial Services Applications / Common Core (Netty) (14.5-14.7)
Oracle Financial Services Applications / Dashboard (Netty) (14.5-14.7)
Oracle Financial Services Applications / Infrastructure (Netty) (14.5-14.7)
Oracle Financial Services Applications / Onboarding Batch Processes (Netty) (14.5-14.7)
Oracle Financial Services Applications / Reports (Netty) (14.5-14.7)
Oracle Financial Services Applications / Security (Netty) (14.5-14.7)
Oracle Financial Services Applications / UI (Netty) (18.3, 19.1, 19.2, 21.1, 22.1, 22.2)
Oracle Financial Services Applications / UI (Netty) (2.7)
Oracle Financial Services Applications / UI (Netty) (2.7)
Oracle Fusion Middleware / Security Framework (Netty) (12.2.1.4.0)
Oracle Fusion Middleware / Third Party (Netty) (14.1.1.0.0, 12.2.1.4.0)
Oracle PeopleSoft / Elastic Search (Netty) (8.59, 8.60)
Oracle TimesTen In-Memory Database / EM TimesTen plug-in (Netty) (Prior to 22.1.1.18.0, Prior to 18.1.4.39.0)

Oracle components and versions

Family	Component	Versions, as Oracle lists them	Read as
Oracle Analytics	Analytics Server (Netty)	6.4.0.0.0	6.4.0.0.0
Oracle Communications	Configuration (Netty)	23.1.3	23.1.3
Oracle Communications	General (Netty)	9.0.0-9.0.2
Oracle Communications	Install/Upgrade (Netty)	23.1.0-23.1.7, 23.2.0-23.2.2
Oracle Communications	Platform (Netty)	23.1.3	23.1.3
Oracle Communications	Third Party (Netty)	23.2.0	23.2.0
Oracle Communications Applications	Common fns (Netty)	12.0.6.0	12.0.6.0
Oracle Communications Applications	HTTPGW (Netty)	12.0.0.4-12.0.0.8
Oracle Financial Services Applications	Accessibility (Netty)	14.5-14.7
Oracle Financial Services Applications	Common (Netty)	14.5-14.7
Oracle Financial Services Applications	Common Core (Netty)	14.5-14.7
Oracle Financial Services Applications	Dashboard (Netty)	14.5-14.7
Oracle Financial Services Applications	Infrastructure (Netty)	14.5-14.7
Oracle Financial Services Applications	Onboarding Batch Processes (Netty)	14.5-14.7
Oracle Financial Services Applications	Reports (Netty)	14.5-14.7
Oracle Financial Services Applications	Security (Netty)	14.5-14.7
Oracle Financial Services Applications	UI (Netty)	2.7	2.7 · 18.3 · 19.1 · 19.2 · 21.1 · 22.1 · 22.2
Oracle Fusion Middleware	Security Framework (Netty)	12.2.1.4.0	12.2.1.4.0
Oracle Fusion Middleware	Third Party (Netty)	14.1.1.0.0, 12.2.1.4.0	12.2.1.4.0 · 14.1.1.0.0
Oracle NoSQL Database	Administration (Netty)	Prior to 19.5.40, Prior to 20.3.38, Prior to 21.2.30, Prior to 22.3.94, Prior to 23.1.29
Oracle PeopleSoft	Elastic Search (Netty)	8.59, 8.60	8.59 · 8.60
Oracle TimesTen In-Memory Database	EM TimesTen plug-in (Netty)	Prior to 22.1.1.18.0, Prior to 18.1.4.39.0
Oracle Utilities Applications	NMS Monitor (Netty)	2.5.0.1, 2.5.0.2, 2.6.0.0	2.5.0.1 · 2.5.0.2 · 2.6.0.0

Family

Component

Versions, as Oracle lists them

Read as

Oracle Analytics

Analytics Server (Netty)

6.4.0.0.0

Oracle Communications

Configuration (Netty)

23.1.3

Oracle Communications

General (Netty)

9.0.0-9.0.2

Oracle Communications

Install/Upgrade (Netty)

23.1.0-23.1.7, 23.2.0-23.2.2

Oracle Communications

Platform (Netty)

23.1.3

Oracle Communications

Third Party (Netty)

23.2.0

Oracle Communications Applications

Common fns (Netty)

12.0.6.0

Oracle Communications Applications

HTTPGW (Netty)

12.0.0.4-12.0.0.8

Oracle Financial Services Applications

Accessibility (Netty)

14.5-14.7

Oracle Financial Services Applications

Common (Netty)

14.5-14.7

Oracle Financial Services Applications

Common Core (Netty)

14.5-14.7

Oracle Financial Services Applications

Dashboard (Netty)

14.5-14.7

Oracle Financial Services Applications

Infrastructure (Netty)

14.5-14.7

Oracle Financial Services Applications

Onboarding Batch Processes (Netty)

14.5-14.7

Oracle Financial Services Applications

Reports (Netty)

14.5-14.7

Oracle Financial Services Applications

Security (Netty)

14.5-14.7

Oracle Financial Services Applications

UI (Netty)

2.7

2.7 · 18.3 · 19.1 · 19.2 · 21.1 · 22.1 · 22.2

Oracle Fusion Middleware

Security Framework (Netty)

12.2.1.4.0

Oracle Fusion Middleware

Third Party (Netty)

14.1.1.0.0, 12.2.1.4.0

12.2.1.4.0 · 14.1.1.0.0

Oracle NoSQL Database

Administration (Netty)

Prior to 19.5.40, Prior to 20.3.38, Prior to 21.2.30, Prior to 22.3.94, Prior to 23.1.29

Oracle PeopleSoft

Elastic Search (Netty)

8.59, 8.60

8.59 · 8.60

Oracle TimesTen In-Memory Database

EM TimesTen plug-in (Netty)

Prior to 22.1.1.18.0, Prior to 18.1.4.39.0

Oracle Utilities Applications

NMS Monitor (Netty)

2.5.0.1, 2.5.0.2, 2.6.0.0

2.5.0.1 · 2.5.0.2 · 2.6.0.0

Maven packages

Affected and fixed versions, from OSV.dev

Package Introduced Fixed Last affected

io.netty:netty-handler 0 4.1.94.Final unbounded

Package	Introduced	Fixed	Last affected
`io.netty:netty-handler`	0	`4.1.94.Final`	unbounded

Products and versions

2 products, 2 version entries

Source	Vendor	Product	Scheme	Affected versions
osv	io.netty	netty-handler	generic	＜ 4.1.94
nvd	netty	netty	generic	＜ 4.1.94

Source

Vendor

Product

Scheme

Affected versions

osv

io.netty

netty-handler

generic

＜ 4.1.94

nvd

netty

generic

＜ 4.1.94

References

URL	Tags
https://github.com/netty/netty/commit/535da17e45201ae4278c0479e6162bb4127d4c32	commit
https://github.com/netty/netty/security/advisories/GHSA-6mjq-h674-j845	WEB
https://github.com/netty/netty	PACKAGE
https://security.netapp.com/advisory/ntap-20230803-0001	WEB
https://security.netapp.com/advisory/ntap-20240621-0007	WEB
https://www.debian.org/security/2023/dsa-5558	WEB
https://security.netapp.com/advisory/ntap-20230803-0001/
https://security.netapp.com/advisory/ntap-20240621-0007/

URL

Timeline

Published	2023-06-22	By the CVE Program.
NVD record modified	2026-06-17	NVD's own last-modified date for this record.

Published

2023-06-22

By the CVE Program.

NVD record modified

2026-06-17

NVD's own last-modified date for this record.

How VRT decided (17 of 24 rules ran)

17 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification no match A researcher's recorded decision for this specific CVE

5 manual classification no match Manual classification of this CVE in the legacy dataset

6 non-java-upstream no match A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component no match The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side no match Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven matched In scope Maven packages: io.netty:netty-handler

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint matched Mitigation candidate References include candidate fix URL (commit tier): https://github.com/netty/netty/commit/535da17e45201ae4278c0479e6162bb4127d4c32

18 open-source-maven skipped The affected package being open source on Maven, so the fix can be read

19 poc-derivable skipped An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit skipped Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match no match A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc skipped Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold withheld CVE ships in Oracle Critical Patch Update January 2024, Oracle Critical Patch Update October 2023 (CPU) — Oracle treats it as urgent, so severity does not settle it

24 no-exploit-published decided it matched No exploit published No exploit code has been published, and an upstream fix path does exist, so the remediation half of the candidacy still holds.

Products the scope rules checked

The products this CVE's record names, and whether VRT tracks each one. The scope rules decided on these.

Vendor Product Tracked CPE Source

netty netty tracked cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* yaml

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