Skip to content
Fencer Vulns
medium 6.5

CVE-2023-34462 json

netty-handler SniHandler 16MB allocation

published 2023-06-20 3 y ago modified 2026-09-10 1 mo ago also GHSA-6mjq-h674-j845 , EUVD-2023-1713

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.5%
EPSS 2.5% chance of exploitation in 30 days, percentile 84%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven io.netty:netty-handler 4.1.94.Final
  • netty netty 4.1.94
  • netty Debian 12 1:4.1.48-7+deb12u1
  • netty Debian 14, Debian 13 1:4.1.48-8

debian advisories DEBIAN-CVE-2023-34462

  • netty Ubuntu 22.04 LTS 1:4.1.48-4+deb11u2build0.22.04.1
  • netty Ubuntu 24.04 LTS 1:4.1.48-9

ubuntu advisories UBUNTU-CVE-2023-34462

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

  • eap7-netty jboss enterprise application platform 7.4 4.1.94-1.Final_redhat_00001.1.el8eap
  • eap7-wildfly jboss enterprise application platform 7.4 7.4.13-8.GA_redhat_00001.1.el8eap
  • eap7-resteasy jboss enterprise application platform 7.4 3.15.8-1.Final_redhat_00001.1.el8eap
  • eap7-undertow jboss enterprise application platform 7.4 2.2.26-1.SP1_redhat_00001.1.el8eap
  • eap7-hibernate jboss enterprise application platform 7.4 5.3.31-1.Final_redhat_00001.1.el8eap
  • eap7-netty-all jboss enterprise application platform 7.4 4.1.94-1.Final_redhat_00001.1.el8eap
  • eap7-hal-console jboss enterprise application platform 7.4 3.3.19-1.Final_redhat_00001.1.el8eap
  • eap7-ironjacamar jboss enterprise application platform 7.4 1.5.15-1.Final_redhat_00001.1.el8eap

red hat advisories RHSA-2023:5485RHSA-2023:5486RHSA-2023:5484

  • netty-tcnative SLE Real Time 15 SP3, SLE Module for Development Tools 15 SP5, SLE Module for Development Tools 15 SP4 +2 more 2.0.61-150200.3.13.1
  • netty SLE Module for Package Hub 15 SP5, openSUSE Leap 15.5, openSUSE Leap 15.4 4.1.94-150200.4.17.1

suse advisories SUSE-SU-2023:2974-1

  • netty openSUSE Tumbleweed 4.1.114-1.1

opensuse advisories openSUSE-SU-2024:14442-1

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-2023-34462 updated cvss 6.5

netty: SniHandler 16MB allocation leads to OOM

  • Red Hat A-MQ Clients 2 netty netty Red Hat Migration Toolkit for Applications 6 org.jboss.windup-windup-parent Red Hat Migration Toolkit for Runtimes org.jboss.windup-windup-parent
    affected: workaround, no fix available “Configuration of SniHandler with an idle timeout will mitigate this issue.”
  • Red Hat A-MQ Online netty netty
    affected: workaround, no fix planned “Configuration of SniHandler with an idle timeout will mitigate this issue.”
  • Red Hat build of Apache Camel for Spring Boot 3 netty netty Red Hat build of OptaPlanner 8 netty netty
    affected: workaround, no fix available “Configuration of SniHandler with an idle timeout will mitigate this issue.”
  • Red Hat Decision Manager 7 netty netty Red Hat Enterprise Linux 8 log4j, log4j-jcl, log4j-web, log4j-slf4j Red Hat Enterprise Linux 9 log4j, log4j-jcl, log4j-slf4j Red Hat Fuse 7 netty netty
    affected: workaround, no fix planned “Configuration of SniHandler with an idle timeout will mitigate this issue.”
  • Red Hat Integration Camel Quarkus 2 netty netty
    affected: workaround, no fix available “Configuration of SniHandler with an idle timeout will mitigate this issue.”
  • Red Hat JBoss Data Grid 7 netty netty Red Hat JBoss Enterprise Application Platform 6 netty netty
    affected: workaround, no fix planned “Configuration of SniHandler with an idle timeout will mitigate this issue.”
  • Red Hat JBoss Enterprise Application Platform Expansion Pack netty netty
    affected: workaround, no fix available “Configuration of SniHandler with an idle timeout will mitigate this issue.”
  • Red Hat JBoss Fuse Service Works 6 netty netty Red Hat OpenShift Application Runtimes netty netty Red Hat Process Automation 7 netty netty Red Hat Single Sign-On 7 netty netty
    affected: workaround, no fix planned “Configuration of SniHandler with an idle timeout will mitigate this issue.”
show 15 more
  • Red Hat streams for Apache Kafka netty netty
    affected: workaround, no fix available “Configuration of SniHandler with an idle timeout will mitigate this issue.”
  • Red Hat Cryostat 2 on RHEL 8 cryostat-tech-preview/cryostat-rhel8 2.4.0-2, cryostat-tech-preview/jfr-datasource-rhel8 2.4.0-2, cryostat-tech-preview/cryostat-reports-rhel8 2.4.0-2, cryostat-tech-preview/cryostat-rhel8-operator 2.4.0-3, cryostat-tech-preview/cryostat-operator-bundle 2.4.0-2, cryostat-tech-preview/cryostat-grafana-dashboard-rhel8 2.4.0-2
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:7669
  • Red Hat AMQ Broker 7
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:5946
  • Red Hat AMQ Clients
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:7697
  • Red Hat AMQ Streams 2.5.0
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:5165
  • Red Hat build of Quarkus 2.13.9
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:7700
  • Red Hat Data Grid 8.4.4
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:5396
  • Red Hat JBoss EAP 7.4 for RHEL 7 Server eap7-netty 4.1.94-1.Final_redhat_00001.1.el7eap, eap7-netty-all 4.1.94-1.Final_redhat_00001.1.el7eap, eap7-netty-codec 4.1.94-1.Final_redhat_00001.1.el7eap, eap7-netty-buffer 4.1.94-1.Final_redhat_00001.1.el7eap, eap7-netty-common 4.1.94-1.Final_redhat_00001.1.el7eap, eap7-netty-handler 4.1.94-1.Final_redhat_00001.1.el7eap, +23 more
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:5484
  • Red Hat JBoss EAP 7.4 for RHEL 8 eap7-netty 4.1.94-1.Final_redhat_00001.1.el8eap, eap7-netty-all 4.1.94-1.Final_redhat_00001.1.el8eap, eap7-netty-codec 4.1.94-1.Final_redhat_00001.1.el8eap, eap7-netty-buffer 4.1.94-1.Final_redhat_00001.1.el8eap, eap7-netty-common 4.1.94-1.Final_redhat_00001.1.el8eap, eap7-netty-handler 4.1.94-1.Final_redhat_00001.1.el8eap, +23 more
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:5485
  • Red Hat JBoss EAP 7.4 for RHEL 9 eap7-netty 4.1.94-1.Final_redhat_00001.1.el9eap, eap7-netty-codec 4.1.94-1.Final_redhat_00001.1.el9eap, eap7-netty-buffer 4.1.94-1.Final_redhat_00001.1.el9eap, eap7-netty-common 4.1.94-1.Final_redhat_00001.1.el9eap, eap7-netty-handler 4.1.94-1.Final_redhat_00001.1.el9eap, eap7-netty-resolver 4.1.94-1.Final_redhat_00001.1.el9eap, +22 more
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:5486
  • Red Hat JBoss Enterprise Application Platform netty-handler 4.1.94.Final-redhat-00001
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:5488
  • Red Hat RHINT Camel-K 1.10.5
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2024:0148
  • Red Hat RHINT Camel-Springboot 4.0.0
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:5441
  • Red Hat RHINT Service Registry 2.5.4 GA
    fixed: vendor fix “Configuration of SniHandler with an idle timeout will mitigate this issue.” RHSA-2023:7653
  • Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/elasticsearch6-rhel8 Red Hat build of Debezium 1 netty netty Red Hat build of Debezium 2 netty netty Red Hat JBoss EAP 7.4 for RHEL 7 Server eap7-wildfly 7.4.13-8.GA_redhat_00001.1.el7eap, eap7-bouncycastle 1.76.0-4.redhat_00001.1.el7eap, eap7-undertow 2.2.26-1.SP1_redhat_00001.1.el7eap, eap7-resteasy 3.15.8-1.Final_redhat_00001.1.el7eap, eap7-bouncycastle-pg 1.76.0-4.redhat_00001.1.el7eap, eap7-hibernate 5.3.31-1.Final_redhat_00001.1.el7eap, +66 more Red Hat JBoss EAP 7.4 for RHEL 8 eap7-wildfly 7.4.13-8.GA_redhat_00001.1.el8eap, eap7-bouncycastle 1.76.0-4.redhat_00001.1.el8eap, eap7-undertow 2.2.26-1.SP1_redhat_00001.1.el8eap, eap7-resteasy 3.15.8-1.Final_redhat_00001.1.el8eap, eap7-bouncycastle-pg 1.76.0-4.redhat_00001.1.el8eap, eap7-hibernate 5.3.31-1.Final_redhat_00001.1.el8eap, +67 more Red Hat JBoss EAP 7.4 for RHEL 9 eap7-wildfly 7.4.13-8.GA_redhat_00001.1.el9eap, eap7-bouncycastle 1.76.0-4.redhat_00001.1.el9eap, eap7-undertow 2.2.26-1.SP1_redhat_00001.1.el9eap, eap7-resteasy 3.15.8-1.Final_redhat_00001.1.el9eap, eap7-bouncycastle-pg 1.76.0-4.redhat_00001.1.el9eap, eap7-hibernate 5.3.31-1.Final_redhat_00001.1.el9eap, +65 more
    +2 more products
    Red Hat JBoss Enterprise Application Platform pom.xml, c3 0.6.0, c3 0.7.1, d3 5.9.2, fs 2.1.2, ip 2.0.0, +1550 more Red Hat JBoss Enterprise Application Platform 8 netty netty
    not affected: vulnerable code not present

2 more not affected in the full advisory

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
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

2.46% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/netty/netty/security/advisories/GHSA-6mjq-h674-j845 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven io.netty:netty-handler
<4.1.94.Final
4.1.94.Final

Affected products

  • netty netty

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-770 Allocation of Resources Without Limits or Throttling

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.