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Fencer Vulns
medium 4.8

CVE-2020-10687 json

HTTP Request Smuggling in Undertow

published 2020-09-23 6 y ago modified 2026-06-17 4 mo ago also GHSA-p9w3-gwc2-cr49 , EUVD-2021-0851

cvss
4.8
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 69%
public exploits
0
none known

Summary

A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.

Patch / fix

  • maven io.undertow:undertow-core 2.2.0.Final
  • redhat undertow 2.2.0
  • undertow Debian 14 2.2.0-1

debian advisories DEBIAN-CVE-2020-10687

  • eap7-dom4j jboss enterprise application platform 7.3, jboss enterprise application platform 7.2 2.1.3-1.redhat_00001.1.el8eap
  • eap7-wildfly jboss enterprise application platform 7.2 7.2.9-4.GA_redhat_00003.1.el8eap
  • eap7-resteasy jboss enterprise application platform 7.2 3.6.1-10.SP9_redhat_00001.1.el8eap
  • eap7-undertow jboss enterprise application platform 7.3, jboss enterprise application platform 7.2 2.0.30-4.SP4_redhat_00001.1.el8eap
  • eap7-weld-ejb jboss enterprise application platform 7.2 3.0.6-4.Final_redhat_00004.1.el8eap
  • eap7-weld-jta jboss enterprise application platform 7.2 3.0.6-4.Final_redhat_00004.1.el8eap
  • eap7-weld-web jboss enterprise application platform 7.2 3.0.6-4.Final_redhat_00004.1.el8eap
  • eap7-hibernate jboss enterprise application platform 7.3, jboss enterprise application platform 7.2 5.3.17-1.Final_redhat_00001.1.el8eap

red hat advisories RHSA-2020:3639RHSA-2020:3638RHSA-2020:3637RHSA-2020:3463RHSA-2020:3462RHSA-2020:3461

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-2020-10687 updated cvss 4.8

Undertow: Incomplete fix for CVE-2017-2666 due to permitting invalid characters in HTTP requests

  • Red Hat JBoss Enterprise Application Platform Continuous Delivery wildfly-undertow Red Hat JBoss Fuse 6 wildfly-undertow
    affected: no fix planned “Out of support scope”
  • Red Hat Fuse 7.7.0
    fixed: vendor fix RHSA-2020:3192
  • Red Hat JBoss EAP 7.2 for RHEL 6 Server eap7-dom4j 2.1.3-1.redhat_00001.1.el6eap, eap7-wildfly 7.2.9-4.GA_redhat_00003.1.el6eap, eap7-resteasy 3.6.1-10.SP9_redhat_00001.1.el6eap, eap7-undertow 2.0.30-4.SP4_redhat_00001.1.el6eap, eap7-weld-ejb 3.0.6-4.Final_redhat_00004.1.el6eap, eap7-weld-jta 3.0.6-4.Final_redhat_00004.1.el6eap, +83 more
    fixed: vendor fix RHSA-2020:3637
  • Red Hat JBoss EAP 7.2 for RHEL 7 Server eap7-dom4j 2.1.3-1.redhat_00001.1.el7eap, eap7-wildfly 7.2.9-4.GA_redhat_00003.1.el7eap, eap7-resteasy 3.6.1-10.SP9_redhat_00001.1.el7eap, eap7-undertow 2.0.30-4.SP4_redhat_00001.1.el7eap, eap7-weld-ejb 3.0.6-4.Final_redhat_00004.1.el7eap, eap7-weld-jta 3.0.6-4.Final_redhat_00004.1.el7eap, +85 more
    fixed: vendor fix RHSA-2020:3638
  • Red Hat JBoss EAP 7.2 for RHEL 8 eap7-dom4j 2.1.3-1.redhat_00001.1.el8eap, eap7-wildfly 7.2.9-4.GA_redhat_00003.1.el8eap, eap7-resteasy 3.6.1-10.SP9_redhat_00001.1.el8eap, eap7-undertow 2.0.30-4.SP4_redhat_00001.1.el8eap, eap7-weld-ejb 3.0.6-4.Final_redhat_00004.1.el8eap, eap7-weld-jta 3.0.6-4.Final_redhat_00004.1.el8eap, +83 more
    fixed: vendor fix RHSA-2020:3639
  • Red Hat JBoss EAP 7.3 for BaseOS-8 eap7-dom4j 2.1.3-1.redhat_00001.1.el8eap, eap7-guava 30.1.0-1.redhat_00001.1.el8eap, eap7-wildfly 7.3.2-4.GA_redhat_00002.1.el8eap, eap7-wildfly 7.3.6-1.GA_redhat_00002.1.el8eap, eap7-netty 4.1.48-1.Final_redhat_00001.1.el8eap, eap7-bouncycastle 1.68.0-1.redhat_00001.1.el8eap, +156 more
    fixed: vendor fix RHSA-2021:0874
  • Red Hat JBoss EAP 7.3 for RHEL 6 Server eap7-dom4j 2.1.3-1.redhat_00001.1.el6eap, eap7-guava 30.1.0-1.redhat_00001.1.el6eap, eap7-wildfly 7.3.2-4.GA_redhat_00002.1.el6eap, eap7-wildfly 7.3.6-1.GA_redhat_00002.1.el6eap, eap7-netty 4.1.48-1.Final_redhat_00001.1.el6eap, eap7-bouncycastle 1.68.0-1.redhat_00001.1.el6eap, +156 more
    fixed: vendor fix RHSA-2021:0872
  • Red Hat JBoss EAP 7.3 for RHEL 7 Server eap7-dom4j 2.1.3-1.redhat_00001.1.el7eap, eap7-guava 30.1.0-1.redhat_00001.1.el7eap, eap7-wildfly 7.3.2-4.GA_redhat_00002.1.el7eap, eap7-wildfly 7.3.6-1.GA_redhat_00002.1.el7eap, eap7-netty 4.1.48-1.Final_redhat_00001.1.el7eap, eap7-bouncycastle 1.68.0-1.redhat_00001.1.el7eap, +160 more
    fixed: vendor fix RHSA-2021:0873
show 2 more
  • Red Hat JBoss Enterprise Application Platform 7
    fixed: vendor fix RHSA-2020:3464
  • Red Hat Single Sign-On 7.4.2
    fixed: vendor fix RHSA-2020:3501

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

1.23% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:P/I:P/A:N
GitHub 3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
maven io.undertow:undertow-core
<2.2.0.Final
2.2.0.Final

Affected products

  • n/a Undertow

Classification

Weakness
  • CWE-444 Inconsistent Interpretation of HTTP Requests

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.