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Fencer Vulns
medium 5.9

CVE-2021-3597 json

undertow Race Condition vulnerability

published 2022-05-24 4 y ago modified 2026-06-17 4 mo ago also GHSA-mfhv-gwf8-4m88 , EUVD-2022-4550

cvss
5.9
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 67%
public exploits
0
none known

Summary

A flaw was found in undertow. The HTTP2SourceChannel fails to write the final frame under some circumstances, resulting in a denial of service. The highest threat from this vulnerability is availability. This flaw affects Undertow versions prior to 2.0.35.SP1, prior to 2.2.6.SP1, prior to 2.2.7.SP1, prior to 2.0.36.SP1, prior to 2.2.9.Final and prior to 2.0.39.Final.

Patch / fix

  • maven io.undertow:undertow-core 2.0.39.Final, 2.2.9.Final
  • redhat undertow 2.0.35, 2.2.6
  • undertow Debian 14 2.2.10-1

debian advisories DEBIAN-CVE-2021-3597

  • eap7-netty jboss enterprise application platform 7.4 4.1.63-1.Final_redhat_00001.1.el8eap
  • eap7-wildfly jboss enterprise application platform 7.4 7.4.1-2.GA_redhat_00003.1.el8eap
  • eap7-undertow jboss enterprise application platform 7.4 2.2.9-2.SP1_redhat_00001.1.el8eap
  • eap7-velocity jboss enterprise application platform 7.4 2.3.0-1.redhat_00001.1.el8eap
  • eap7-netty-all jboss enterprise application platform 7.4 4.1.63-1.Final_redhat_00001.1.el8eap
  • eap7-jakarta-el jboss enterprise application platform 7.4, jboss enterprise application platform 7.3 3.0.3-2.redhat_00006.1.el8eap
  • eap7-wildfly-elytron jboss enterprise application platform 7.4 1.15.5-1.Final_redhat_00001.1.el8eap
  • eap7-wildfly-modules jboss enterprise application platform 7.4 7.4.1-2.GA_redhat_00003.1.el8eap

red hat advisories RHSA-2021:3658RHSA-2021:3656RHSA-2021:3466RHSA-2021:3468RHSA-2021:3467

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-2021-3597 updated cvss 5.9

undertow: HTTP2SourceChannel fails to write final frame under some circumstances may lead to DoS

  • Red Hat JBoss Data Grid 7 undertow undertow
    affected: no fix planned “Out of support scope”
  • Red Hat JBoss Enterprise Application Platform Expansion Pack undertow undertow
    affected: no fix available
  • Red Hat JBoss Fuse 6 undertow undertow Red Hat OpenShift Application Runtimes undertow undertow
    affected: no fix planned “Out of support scope”
  • Red Hat OpenStack Platform 13 (Queens) opendaylight
    affected: no fix planned “Will not fix”
  • Red Hat support for Spring Boot undertow undertow
    affected: no fix available
  • Red Hat EAP 7.3.9 release
    fixed: vendor fix RHSA-2021:3471
  • Red Hat EAP-XP 2.0.0 via EAP 7.3.x base
    fixed: vendor fix RHSA-2021:3516
  • Red Hat Fuse 7.10
    fixed: vendor fix RHSA-2021:5134
show 9 more
  • Red Hat JBoss EAP 7.3 for BaseOS-8 eap7-jakarta-el 3.0.3-2.redhat_00006.1.el8eap, eap7-wildfly 7.3.9-2.GA_redhat_00002.1.el8eap, eap7-jberet 1.3.9-1.Final_redhat_00001.1.el8eap, eap7-undertow 2.0.39-1.SP2_redhat_00001.1.el8eap, eap7-hibernate 5.3.20-4.SP2_redhat_00001.1.el8eap, eap7-narayana 5.9.12-1.Final_redhat_00001.1.el8eap, +59 more
    fixed: vendor fix RHSA-2021:3468
  • Red Hat JBoss EAP 7.3 for RHEL 6 Server eap7-jakarta-el 3.0.3-2.redhat_00006.1.el6eap, eap7-wildfly 7.3.9-2.GA_redhat_00002.1.el6eap, eap7-jberet 1.3.9-1.Final_redhat_00001.1.el6eap, eap7-undertow 2.0.39-1.SP2_redhat_00001.1.el6eap, eap7-hibernate 5.3.20-4.SP2_redhat_00001.1.el6eap, eap7-narayana 5.9.12-1.Final_redhat_00001.1.el6eap, +59 more
    fixed: vendor fix RHSA-2021:3466
  • Red Hat JBoss EAP 7.3 for RHEL 7 Server eap7-jakarta-el 3.0.3-2.redhat_00006.1.el7eap, eap7-wildfly 7.3.9-2.GA_redhat_00002.1.el7eap, eap7-jberet 1.3.9-1.Final_redhat_00001.1.el7eap, eap7-undertow 2.0.39-1.SP2_redhat_00001.1.el7eap, eap7-hibernate 5.3.20-4.SP2_redhat_00001.1.el7eap, eap7-narayana 5.9.12-1.Final_redhat_00001.1.el7eap, +61 more
    fixed: vendor fix RHSA-2021:3467
  • Red Hat JBoss EAP 7.4 for RHEL 7 Server eap7-undertow 2.2.9-2.SP1_redhat_00001.1.el7eap
    fixed: vendor fix RHSA-2021:3656
  • Red Hat JBoss EAP 7.4 for RHEL 8 eap7-undertow 2.2.9-2.SP1_redhat_00001.1.el8eap
    fixed: vendor fix RHSA-2021:3658
  • Red Hat JBoss Enterprise Application Platform undertow-core 2.2.9.SP1-redhat-00001
    fixed: vendor fix RHSA-2021:3660
  • Red Hat Single Sign-On 7.4.9
    fixed: vendor fix RHSA-2021:3534
  • Red Hat Support for Spring Boot 2.5.10
    fixed: vendor fix RHSA-2022:1179
  • Red Hat build of Quarkus undertow undertow Red Hat Decision Manager 7 undertow undertow Red Hat Integration Camel K 1 undertow undertow Red Hat Integration Camel Quarkus 1 undertow undertow Red Hat Integration Service Registry undertow undertow Red Hat JBoss EAP 7.4 for RHEL 7 Server eap7-yasson 1.0.9-1.redhat_00001.1.el7eap, eap7-velocity 2.3.0-1.redhat_00001.1.el7eap, eap7-xalan-j2 2.7.1-36.redhat_00013.1.el7eap, eap7-jakarta-el 3.0.3-2.redhat_00006.1.el7eap, eap7-wildfly 7.4.1-2.GA_redhat_00003.1.el7eap, eap7-jberet 1.3.9-1.Final_redhat_00001.1.el7eap, +52 more
    +3 more products
    Red Hat JBoss EAP 7.4 for RHEL 8 eap7-yasson 1.0.9-1.redhat_00001.1.el8eap, eap7-velocity 2.3.0-1.redhat_00001.1.el8eap, eap7-xalan-j2 2.7.1-36.redhat_00013.1.el8eap, eap7-jakarta-el 3.0.3-2.redhat_00006.1.el8eap, eap7-wildfly 7.4.1-2.GA_redhat_00003.1.el8eap, eap7-jberet 1.3.9-1.Final_redhat_00001.1.el8eap, +50 more Red Hat JBoss Enterprise Application Platform pom.xml, c3 0.6.0, c3 0.7.1, d3 5.9.2, ms 2.0.0, ms 2.1.2, +1442 more Red Hat Process Automation 7 undertow undertow
    not affected: vulnerable code not present

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

Exploit prediction

1.16% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 2.6 AV:N/AC:H/Au:N/C:N/I:N/A:P
GitHub 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven io.undertow:undertow-core
>=2.1.0, <2.2.9.Final
<2.0.39.Final
2.2.9.Final
2.0.39.Final

Affected products

  • n/a undertow

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

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.