Skip to content
Fencer Vulns
high 7.5

CVE-2021-37137 json

SnappyFrameDecoder doesn't restrict chunk length any may buffer skippable chunks in an unnecessary way

published 2021-09-09 5 y ago modified 2026-10-08 31 d ago also GHSA-9vjp-v76f-g363 , EUVD-2021-2029

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
6.6%
EPSS 6.6% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

The Snappy frame decoder function doesn't restrict the chunk length which may lead to excessive memory usage. Beside this it also may buffer reserved skippable chunks until the whole chunk was received which may lead to excessive memory usage as well. This vulnerability can be triggered by supplying malicious input that decompresses to a very big size (via a network stream or a file) or by sending a huge skippable chunk.

Patch / fix

  • maven io.netty:netty-codec 4.1.68.Final
  • The Netty project Netty 4.1.68Final
  • netty Debian 14, Debian 13, Debian 12 1:4.1.48-6

debian advisories DEBIAN-CVE-2021-37137

  • netty Ubuntu 22.04 LTS 1:4.1.48-4+deb11u1build0.22.04.1
  • netty Ubuntu Pro 16.04 LTS 1:4.0.34-1ubuntu0.1~esm1
  • netty Ubuntu Pro 18.04 LTS 1:4.1.7-4ubuntu0.1+esm2
  • netty Ubuntu Pro 20.04 LTS 1:4.1.45-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2021-37137

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

  • foreman satellite utils 6.12, satellite capsule 6.12, satellite 6.12 3.3.0.17-1.el8sat
  • candlepin satellite 6.12 4.1.15-1.el8sat
  • foreman-cli satellite utils 6.12, satellite 6.12 3.3.0.17-1.el8sat
  • foreman-ec2 satellite 6.12 3.3.0.17-1.el8sat
  • foreman-gce satellite 6.12 3.3.0.17-1.el8sat
  • rubygem-git satellite 6.12 1.11.0-1.el8sat
  • foreman-ovirt satellite 6.12 3.3.0.17-1.el8sat
  • python-django satellite capsule 6.12, satellite 6.12 3.2.14-2.el8pc

red hat advisories RHSA-2025:9583RHSA-2025:9582RHSA-2022:8506RHSA-2022:4918RHSA-2022:4919

  • netty Manager Server Module 4.1 4.1.44.Final-150200.3.4.2
  • netty Manager Server Module 4.3 4.1.44.Final-150400.3.3.2
  • netty Manager Server Module 4.2 4.1.44.Final-150300.4.3.2
  • netty openSUSE Leap 15.3 4.1.75-150200.4.6.2

suse advisories SUSE-SU-2022:3793-1SUSE-SU-2022:3760-1SUSE-SU-2022:3617-1SUSE-SU-2022:1271-1

  • netty openSUSE Tumbleweed 4.1.114-1.1

opensuse advisories openSUSE-SU-2024:14442-1

  • libdb Rocky Linux 8 5.3.28-42.el8_4

rocky linux advisories RLSA-2022:8506

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-2021-37137 updated cvss 7.5

netty-codec: SnappyFrameDecoder doesn't restrict chunk length and may buffer skippable chunks in an unnecessary way

  • Red Hat A-MQ Clients 2 netty-codec
    affected: no fix available
  • Red Hat BPM Suite 6 netty-codec
    affected: no fix planned “Out of support scope”
  • Red Hat build of Quarkus netty-codec Red Hat Integration Camel K 1 netty-codec Red Hat Integration Camel Quarkus 1 netty-codec
    affected: no fix available
  • Red Hat JBoss BRMS 6 netty-codec Red Hat JBoss Data Grid 7 netty-codec Red Hat JBoss Data Virtualization 6 netty-codec Red Hat JBoss Fuse 6 netty-codec Red Hat JBoss Fuse Service Works 6 netty-codec Red Hat OpenShift Container Platform 3.11 openshift3/ose-logging-elasticsearch5
    +3 more products
    Red Hat OpenShift Container Platform 4 openshift4/ose-metering-hadoop, openshift4/ose-logging-elasticsearch6 Red Hat OpenStack Platform 10 (Newton) opendaylight Red Hat OpenStack Platform 13 (Queens) opendaylight
    affected: no fix planned “Out of support scope”
  • Red Hat Single Sign-On 7 netty-codec
    affected: no fix planned “Will not fix”
  • Red Hat OpenShift Logging 5.1 openshift-logging/elasticsearch6-rhel8 v6.8.1-67
    fixed: vendor fix RHSA-2021:5128
  • Red Hat OpenShift Logging 5.2 openshift-logging/elasticsearch6-rhel8 v6.8.1-66, openshift-logging/elasticsearch6-rhel8 v6.8.1-157
    fixed: vendor fix RHSA-2022:2218
  • Red Hat OpenShift Logging 5.3 openshift-logging/elasticsearch6-rhel8 v6.8.1-65, openshift-logging/elasticsearch6-rhel8 v6.8.1-159
    fixed: vendor fix RHSA-2022:2217
show 19 more
  • Red Hat AMQ 7.9.1
    fixed: vendor fix RHSA-2021:4851
  • Red Hat AMQ Streams 2.0.0
    fixed: vendor fix RHSA-2022:0138
  • Red Hat AMQ Streams 2.4.0
    fixed: vendor fix RHSA-2023:3223
  • Red Hat AMQ Streams 2.5.0
    fixed: vendor fix RHSA-2023:5165
  • Red Hat build of Quarkus 2.2.5
    fixed: vendor fix RHSA-2022:0589
  • Red Hat Data Grid 8.3.0
    fixed: vendor fix RHSA-2022:0520
  • Red Hat Fuse 7.10
    fixed: vendor fix RHSA-2021:5134
  • Red Hat JBoss EAP 7.4 for RHEL 7 Server eap7-netty 4.1.72-4.Final_redhat_00001.1.el7eap, eap7-netty-all 4.1.72-4.Final_redhat_00001.1.el7eap, eap7-netty-codec 4.1.72-4.Final_redhat_00001.1.el7eap, eap7-netty-buffer 4.1.72-4.Final_redhat_00001.1.el7eap, eap7-netty-common 4.1.72-4.Final_redhat_00001.1.el7eap, eap7-netty-handler 4.1.72-4.Final_redhat_00001.1.el7eap, +22 more
    fixed: vendor fix RHSA-2022:4918
  • Red Hat JBoss EAP 7.4 for RHEL 8 eap7-netty 4.1.72-4.Final_redhat_00001.1.el8eap, eap7-netty-all 4.1.72-4.Final_redhat_00001.1.el8eap, eap7-netty-codec 4.1.72-4.Final_redhat_00001.1.el8eap, eap7-netty-buffer 4.1.72-4.Final_redhat_00001.1.el8eap, eap7-netty-common 4.1.72-4.Final_redhat_00001.1.el8eap, eap7-netty-handler 4.1.72-4.Final_redhat_00001.1.el8eap, +22 more
    fixed: vendor fix RHSA-2022:4919
  • Red Hat JBoss Enterprise Application Platform netty-codec 4.1.72.Final-redhat-00001
    fixed: vendor fix RHSA-2022:4922
  • Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7 Server eap7-wildfly 7.1.11-4.GA_redhat_00002.1.ep7.el7, eap7-netty 4.1.63-2.Final_redhat_00003.1.ep7.el7, eap7-undertow 1.4.18-16.SP14_redhat_00001.1.ep7.el7, eap7-glassfish-el 3.0.1-4.b08_redhat_00005.1.ep7.el7, eap7-hibernate 5.1.17-3.Final_redhat_00004.1.ep7.el7, eap7-netty-all 4.1.63-2.Final_redhat_00003.1.ep7.el7, +19 more
    fixed: vendor fix RHSA-2025:9582
  • Red Hat JBoss Enterprise Application Platform 7.3 EUS for RHEL 7 Server eap7-wildfly 7.3.14-3.GA_redhat_00002.1.el7eap, eap7-netty 4.1.63-5.Final_redhat_00003.1.el7eap, eap7-jackson-core 2.10.4-3.redhat_00006.1.el7eap, eap7-undertow 2.0.41-4.SP5_redhat_00001.1.el7eap, eap7-netty-all 4.1.63-5.Final_redhat_00003.1.el7eap, eap7-jackson-databind 2.10.4-5.redhat_00006.1.el7eap, +37 more
    fixed: vendor fix RHSA-2025:9583
  • Red Hat Satellite 6.12 for RHEL 8 candlepin 4.1.15-1.el8sat, candlepin-selinux 4.1.15-1.el8sat
    fixed: vendor fix RHSA-2022:8506
  • Red Hat RHINT Camel-Q 2.2.1
    fixed: vendor fix RHSA-2022:1013
  • Red Hat RHINT Service Registry 2.3.0 GA
    fixed: vendor fix RHSA-2022:6835
  • Red Hat RHOL 5.4 for RHEL 8 openshift-logging/elasticsearch6-rhel8 v6.8.1-156
    fixed: vendor fix RHSA-2022:2216
  • Red Hat RHPAM 7.13.0 async
    fixed: vendor fix RHSA-2022:5903
  • Red Hat Vert.x 4.1.5
    fixed: vendor fix RHSA-2021:3959
  • Red Hat OpenShift Logging 5.1 openshift-logging/fluentd-rhel8 v1.7.4-72, openshift-logging/kibana6-rhel8 v6.8.1-75, openshift-logging/eventrouter-rhel8 v0.3.0-65, openshift-logging/elasticsearch-proxy-rhel8 v1.0.0-68, openshift-logging/elasticsearch-rhel8-operator v5.1.5-3, openshift-logging/cluster-logging-rhel8-operator v5.1.5-3, +2 more Red Hat OpenShift Logging 5.2 openshift-logging/fluentd-rhel8 v1.7.4-71, openshift-logging/kibana6-rhel8 v6.8.1-74, openshift-logging/fluentd-rhel8 v1.7.4-176, openshift-logging/kibana6-rhel8 v6.8.1-188, openshift-logging/eventrouter-rhel8 v0.3.0-64, openshift-logging/eventrouter-rhel8 v0.3.0-161, +14 more Red Hat OpenShift Logging 5.3 openshift-logging/fluentd-rhel8 v1.7.4-70, openshift-logging/kibana6-rhel8 v6.8.1-73, openshift-logging/fluentd-rhel8 v1.7.4-178, openshift-logging/kibana6-rhel8 v6.8.1-190, openshift-logging/eventrouter-rhel8 v0.3.0-63, openshift-logging/eventrouter-rhel8 v0.3.0-164, +14 more Red Hat Integration Service Registry netty-codec
    not affected: vulnerable code not present

6 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
yes
Technical impact
partial
Assessed
31 d ago

Exploit prediction

6.57% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven io.netty:netty-codec
>=4.0.0, <4.1.68.Final
4.1.68.Final
maven org.jboss.netty:netty
all versions
 no fix listed
maven io.netty:netty
all versions
 no fix listed

Affected products

  • The Netty project Netty

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

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.