CVE-2021-3597

22

FAUCET Score

CVE-2021-3597 is a denial-of-service vulnerability in Undertow, affecting versions prior to 2.0.35.SP1, 2.2.6.SP1, 2.2.7.SP1, 2.0.36.SP1, 2.2.9.Final, and 2.0.39.Final, as well as products like NetApp and Red Hat. This flaw, rated Medium severity (CVSS 5.9), allows an unauthenticated attacker to cause a denial of service due to the HTTP2SourceChannel failing to write the final frame under specific circumstances. There is no evidence of active exploitation, public exploit code, or significant community discussion surrounding this vulnerability.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		1.0CPE matchmatch criteria	cpe:2.3:a:redhat:fuse:1.0:::::::*
		Range not provided by sourceCPE matchmatch criteria	cpe:2.3:a:redhat:jboss_enterprise_application_platform:-::::text-only:::
		Range not provided by sourceCPE matchmatch criteria	cpe:2.3:a:redhat:openshift_application_runtimes:-::::text-only:::
		Range not provided by sourceCPE matchmatch criteria	cpe:2.3:a:redhat:single_sign-on:-::::text-only:::
		< 2.0.35CPE matchmatch criteria	cpe:2.3:a:redhat:undertow::::::::

CVSS Data

CVSS version used by this source: 3.1

5.9MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

Exploitability Score

2.2

Impact Score

3.6

CvssVersion

3.1

Exploit Intelligence

EPSS Score

1.08%

Probability of exploitation in next 30 days

EPSS Percentile

61.8%

Percentile rank of EPSS score among Peer Group

As of 2026-07-27

Model: v2026.06.15

This CVE's current EPSS score of 0.0108 is in the 23rd percentile among its peer group of 19,958 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (54)

mavenpatch availablevia ghsa

Product: io.undertow:undertow-coreFixed in: 2.0.39.Final

mavenpatch availablevia ghsa

Product: io.undertow:undertow-coreFixed in: 2.2.9.Final

redhatpatch availablevia redhat_api

Product: Red Hat EAP-XP 2.0.0 via EAP 7.3.x baseFixed in: undertow

redhatpatch availablevia redhat_api

Product: Red Hat Fuse 7.10Fixed in: undertow

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7Fixed in: undertow

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-apache-commons-io-0:2.10.0-1.redhat_00001.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-hal-console-0:3.2.16-1.Final_redhat_00001.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-hibernate-0:5.3.20-4.SP2_redhat_00001.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-ironjacamar-0:1.4.35-1.Final_redhat_00001.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-jakarta-el-0:3.0.3-2.redhat_00006.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-jberet-0:1.3.9-1.Final_redhat_00001.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-jboss-remoting-0:5.0.23-2.SP1_redhat_00001.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-jboss-server-migration-0:1.7.2-9.Final_redhat_00010.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-narayana-0:5.9.12-1.Final_redhat_00001.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-picketbox-0:5.0.3-9.Final_redhat_00008.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-undertow-0:2.0.39-1.SP2_redhat_00001.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-wildfly-0:7.3.9-2.GA_redhat_00002.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-wildfly-http-client-0:1.0.29-1.Final_redhat_00002.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 6Fixed in: eap7-wildfly-transaction-client-0:1.1.14-2.Final_redhat_00001.1.el6eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-apache-commons-io-0:2.10.0-1.redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-hal-console-0:3.2.16-1.Final_redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-hibernate-0:5.3.20-4.SP2_redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-ironjacamar-0:1.4.35-1.Final_redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-jakarta-el-0:3.0.3-2.redhat_00006.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-jberet-0:1.3.9-1.Final_redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-jboss-remoting-0:5.0.23-2.SP1_redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-jboss-server-migration-0:1.7.2-9.Final_redhat_00010.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-narayana-0:5.9.12-1.Final_redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-picketbox-0:5.0.3-9.Final_redhat_00008.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-undertow-0:2.0.39-1.SP2_redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-wildfly-0:7.3.9-2.GA_redhat_00002.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-wildfly-http-client-0:1.0.29-1.Final_redhat_00002.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 7Fixed in: eap7-wildfly-transaction-client-0:1.1.14-2.Final_redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-apache-commons-io-0:2.10.0-1.redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-hal-console-0:3.2.16-1.Final_redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-hibernate-0:5.3.20-4.SP2_redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-ironjacamar-0:1.4.35-1.Final_redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-jakarta-el-0:3.0.3-2.redhat_00006.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-jberet-0:1.3.9-1.Final_redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-jboss-remoting-0:5.0.23-2.SP1_redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-narayana-0:5.9.12-1.Final_redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-picketbox-0:5.0.3-9.Final_redhat_00008.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-undertow-0:2.0.39-1.SP2_redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-wildfly-0:7.3.9-2.GA_redhat_00002.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-wildfly-http-client-0:1.0.29-1.Final_redhat_00002.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-wildfly-transaction-client-0:1.1.14-2.Final_redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.4 for RHEL 8Fixed in: eap7-undertow-0:2.2.9-2.SP1_redhat_00001.1.el8eap

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.4 on RHEL 7Fixed in: eap7-undertow-0:2.2.9-2.SP1_redhat_00001.1.el7eap

redhatpatch availablevia redhat_api

Product: Red Hat Single Sign-On 7.4.9Fixed in: undertow

redhatpatch availablevia redhat_api

Product: Red Hat Support for Spring Boot 2.5.10Fixed in: undertow

redhatpatch availablevia redhat_api

Product: Red Hat JBoss Enterprise Application Platform 7.3 for RHEL 8Fixed in: eap7-jboss-server-migration-0:1.7.2-9.Final_redhat_00010.1.el8eap

redhatpatch availablevia redhat_api

Product: EAP 7.3.9 releaseFixed in: undertow

redhatno patchvia redhat_api

Product: Red Hat support for Spring BootFixed in: undertow

redhatend of lifevia redhat_api

Product: Red Hat OpenStack Platform 13 (Queens)Fixed in: opendaylight

Vendor Advisories (2)

mavenGHSA-mfhv-gwf8-4m88medium

undertow Race Condition vulnerability

redhatCVE-2021-3597Moderate

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

References

bugzilla.redhat.com / show_bug.cgi

Issue TrackingThird Party Advisory

security.netapp.com / advisory/ntap-20220804-0003

Third Party Advisory