CVE-2019-20444: XSS
Published Jan 29, 2020
·Updated
A HTTP smuggling flaw was found in HttpObjectDecoder.java in Netty in versions prior to version 4.1.44. HTTP headers with an invalid fold, in this case CRLF (carriage return, line feed) without being followed by SP (space) or HTAB (horizontal tab), result in situations where headers can be misread. Data integrity is the highest threat with this vulnerability.
Other sources
A vulnerability was found in HttpObjectDecoder.java in Netty before 4.1.44 allows an HTTP header that lacks a colon, which might be interpreted as a separate header with an incorrect syntax, or might be interpreted as an "invalid fold."
Reference: https://github.com/netty/netty/issues/9866 https://github.com/netty/netty/compare/netty-4.1.43.Final...netty-4.1.44.Final
— Red Hat
Netty is vulnerable to HTTP request smuggling, caused by a flaw in the HttpObjectDecoder.java. By sending a specially-crafted request, an attacker could exploit this vulnerability to poison the web cache, bypass web application firewall protection, and conduct XSS attacks.
— IBM
Affected Software
108 affected componentsFixes available
redhat/qpid-proton<0:0.30.0-4.el6_10
0:0.30.0-4.el6_10
redhat/qpid-proton<0:0.30.0-2.el7
0:0.30.0-2.el7
redhat/nodejs-rhea<0:1.0.16-1.el8
0:1.0.16-1.el8
redhat/qpid-proton<0:0.30.0-3.el8
0:0.30.0-3.el8
redhat/eap7-netty<0:4.1.45-1.Final_redhat_00001.1.el6ea
0:4.1.45-1.Final_redhat_00001.1.el6ea
redhat/eap7-activemq-artemis<0:2.9.0-2.redhat_00009.1.el6ea
0:2.9.0-2.redhat_00009.1.el6ea
redhat/eap7-apache-commons-beanutils<0:1.9.4-1.redhat_00002.1.el6ea
0:1.9.4-1.redhat_00002.1.el6ea
redhat/eap7-glassfish-el<0:3.0.1-4.b08_redhat_00003.1.el6ea
0:3.0.1-4.b08_redhat_00003.1.el6ea
redhat/eap7-glassfish-jaxb<0:2.3.3-4.b02_redhat_00001.1.el6ea
0:2.3.3-4.b02_redhat_00001.1.el6ea
redhat/eap7-glassfish-jsf<0:2.3.5-7.SP3_redhat_00005.1.el6ea
0:2.3.5-7.SP3_redhat_00005.1.el6ea
redhat/eap7-hal-console<0:3.0.20-1.Final_redhat_00001.1.el6ea
0:3.0.20-1.Final_redhat_00001.1.el6ea
redhat/eap7-hibernate<0:5.3.15-1.Final_redhat_00001.1.el6ea
0:5.3.15-1.Final_redhat_00001.1.el6ea
redhat/eap7-infinispan<0:9.3.8-1.Final_redhat_00001.1.el6ea
0:9.3.8-1.Final_redhat_00001.1.el6ea
redhat/eap7-ironjacamar<0:1.4.20-1.Final_redhat_00001.1.el6ea
0:1.4.20-1.Final_redhat_00001.1.el6ea
redhat/eap7-jackson-databind<0:2.9.10.2-1.redhat_00001.1.el6ea
0:2.9.10.2-1.redhat_00001.1.el6ea
redhat/eap7-jaegertracing-jaeger-client-java<0:0.34.1-1.redhat_00002.1.el6ea
0:0.34.1-1.redhat_00002.1.el6ea
redhat/eap7-jboss-ejb-client<0:4.0.28-1.Final_redhat_00001.1.el6ea
0:4.0.28-1.Final_redhat_00001.1.el6ea
redhat/eap7-jboss-remoting<0:5.0.17-1.Final_redhat_00001.1.el6ea
0:5.0.17-1.Final_redhat_00001.1.el6ea
redhat/eap7-jboss-server-migration<0:1.3.1-8.Final_redhat_00009.1.el6ea
0:1.3.1-8.Final_redhat_00009.1.el6ea
redhat/eap7-picketlink-bindings<0:2.5.5-23.SP12_redhat_00012.1.el6ea
0:2.5.5-23.SP12_redhat_00012.1.el6ea
redhat/eap7-stax2-api<0:4.2.0-1.redhat_00001.1.el6ea
0:4.2.0-1.redhat_00001.1.el6ea
redhat/eap7-sun-istack-commons<0:3.0.10-1.redhat_00001.1.el6ea
0:3.0.10-1.redhat_00001.1.el6ea
redhat/eap7-thrift<0:0.13.0-1.redhat_00002.1.el6ea
0:0.13.0-1.redhat_00002.1.el6ea
redhat/eap7-wildfly<0:7.2.7-4.GA_redhat_00004.1.el6ea
0:7.2.7-4.GA_redhat_00004.1.el6ea
redhat/eap7-wildfly-http-client<0:1.0.20-1.Final_redhat_00001.1.el6ea
0:1.0.20-1.Final_redhat_00001.1.el6ea
redhat/eap7-wildfly-openssl<0:1.0.9-2.SP03_redhat_00001.1.el6ea
0:1.0.9-2.SP03_redhat_00001.1.el6ea
redhat/eap7-wildfly-transaction-client<0:1.1.9-1.Final_redhat_00001.1.el6ea
0:1.1.9-1.Final_redhat_00001.1.el6ea
redhat/eap7-woodstox-core<0:6.0.3-1.redhat_00001.1.el6ea
0:6.0.3-1.redhat_00001.1.el6ea
redhat/eap7-xml-security<0:2.1.4-1.redhat_00001.1.el6ea
0:2.1.4-1.redhat_00001.1.el6ea
redhat/eap7-netty<0:4.1.45-1.Final_redhat_00001.1.el7ea
0:4.1.45-1.Final_redhat_00001.1.el7ea
redhat/eap7-activemq-artemis<0:2.9.0-2.redhat_00009.1.el7ea
0:2.9.0-2.redhat_00009.1.el7ea
redhat/eap7-apache-commons-beanutils<0:1.9.4-1.redhat_00002.1.el7ea
0:1.9.4-1.redhat_00002.1.el7ea
redhat/eap7-glassfish-el<0:3.0.1-4.b08_redhat_00003.1.el7ea
0:3.0.1-4.b08_redhat_00003.1.el7ea
redhat/eap7-glassfish-jaxb<0:2.3.3-4.b02_redhat_00001.1.el7ea
0:2.3.3-4.b02_redhat_00001.1.el7ea
redhat/eap7-glassfish-jsf<0:2.3.5-7.SP3_redhat_00005.1.el7ea
0:2.3.5-7.SP3_redhat_00005.1.el7ea
redhat/eap7-hal-console<0:3.0.20-1.Final_redhat_00001.1.el7ea
0:3.0.20-1.Final_redhat_00001.1.el7ea
redhat/eap7-hibernate<0:5.3.15-1.Final_redhat_00001.1.el7ea
0:5.3.15-1.Final_redhat_00001.1.el7ea
redhat/eap7-infinispan<0:9.3.8-1.Final_redhat_00001.1.el7ea
0:9.3.8-1.Final_redhat_00001.1.el7ea
redhat/eap7-ironjacamar<0:1.4.20-1.Final_redhat_00001.1.el7ea
0:1.4.20-1.Final_redhat_00001.1.el7ea
redhat/eap7-jackson-databind<0:2.9.10.2-1.redhat_00001.1.el7ea
0:2.9.10.2-1.redhat_00001.1.el7ea
redhat/eap7-jaegertracing-jaeger-client-java<0:0.34.1-1.redhat_00002.1.el7ea
0:0.34.1-1.redhat_00002.1.el7ea
redhat/eap7-jboss-ejb-client<0:4.0.28-1.Final_redhat_00001.1.el7ea
0:4.0.28-1.Final_redhat_00001.1.el7ea
redhat/eap7-jboss-remoting<0:5.0.17-1.Final_redhat_00001.1.el7ea
0:5.0.17-1.Final_redhat_00001.1.el7ea
redhat/eap7-jboss-server-migration<0:1.3.1-8.Final_redhat_00009.1.el7ea
0:1.3.1-8.Final_redhat_00009.1.el7ea
redhat/eap7-picketlink-bindings<0:2.5.5-23.SP12_redhat_00012.1.el7ea
0:2.5.5-23.SP12_redhat_00012.1.el7ea
redhat/eap7-stax2-api<0:4.2.0-1.redhat_00001.1.el7ea
0:4.2.0-1.redhat_00001.1.el7ea
redhat/eap7-sun-istack-commons<0:3.0.10-1.redhat_00001.1.el7ea
0:3.0.10-1.redhat_00001.1.el7ea
redhat/eap7-thrift<0:0.13.0-1.redhat_00002.1.el7ea
0:0.13.0-1.redhat_00002.1.el7ea
redhat/eap7-wildfly<0:7.2.7-4.GA_redhat_00004.1.el7ea
0:7.2.7-4.GA_redhat_00004.1.el7ea
redhat/eap7-wildfly-http-client<0:1.0.20-1.Final_redhat_00001.1.el7ea
0:1.0.20-1.Final_redhat_00001.1.el7ea
redhat/eap7-wildfly-openssl<0:1.0.9-2.SP03_redhat_00001.1.el7ea
0:1.0.9-2.SP03_redhat_00001.1.el7ea
redhat/eap7-wildfly-transaction-client<0:1.1.9-1.Final_redhat_00001.1.el7ea
0:1.1.9-1.Final_redhat_00001.1.el7ea
redhat/eap7-woodstox-core<0:6.0.3-1.redhat_00001.1.el7ea
0:6.0.3-1.redhat_00001.1.el7ea
redhat/eap7-xml-security<0:2.1.4-1.redhat_00001.1.el7ea
0:2.1.4-1.redhat_00001.1.el7ea
redhat/eap7-netty<0:4.1.45-1.Final_redhat_00001.1.el8ea
0:4.1.45-1.Final_redhat_00001.1.el8ea
redhat/eap7-activemq-artemis<0:2.9.0-2.redhat_00009.1.el8ea
0:2.9.0-2.redhat_00009.1.el8ea
redhat/eap7-apache-commons-beanutils<0:1.9.4-1.redhat_00002.1.el8ea
0:1.9.4-1.redhat_00002.1.el8ea
redhat/eap7-glassfish-el<0:3.0.1-4.b08_redhat_00003.1.el8ea
0:3.0.1-4.b08_redhat_00003.1.el8ea
redhat/eap7-glassfish-jaxb<0:2.3.3-4.b02_redhat_00001.1.el8ea
0:2.3.3-4.b02_redhat_00001.1.el8ea
redhat/eap7-glassfish-jsf<0:2.3.5-7.SP3_redhat_00005.1.el8ea
0:2.3.5-7.SP3_redhat_00005.1.el8ea
redhat/eap7-hal-console<0:3.0.20-1.Final_redhat_00001.1.el8ea
0:3.0.20-1.Final_redhat_00001.1.el8ea
redhat/eap7-hibernate<0:5.3.15-1.Final_redhat_00001.1.el8ea
0:5.3.15-1.Final_redhat_00001.1.el8ea
redhat/eap7-infinispan<0:9.3.8-1.Final_redhat_00001.1.el8ea
0:9.3.8-1.Final_redhat_00001.1.el8ea
redhat/eap7-ironjacamar<0:1.4.20-1.Final_redhat_00001.1.el8ea
0:1.4.20-1.Final_redhat_00001.1.el8ea
redhat/eap7-jackson-databind<0:2.9.10.2-1.redhat_00001.1.el8ea
0:2.9.10.2-1.redhat_00001.1.el8ea
redhat/eap7-jaegertracing-jaeger-client-java<0:0.34.1-1.redhat_00002.1.el8ea
0:0.34.1-1.redhat_00002.1.el8ea
redhat/eap7-jboss-ejb-client<0:4.0.28-1.Final_redhat_00001.1.el8ea
0:4.0.28-1.Final_redhat_00001.1.el8ea
redhat/eap7-jboss-remoting<0:5.0.17-1.Final_redhat_00001.1.el8ea
0:5.0.17-1.Final_redhat_00001.1.el8ea
redhat/eap7-jboss-server-migration<0:1.3.1-8.Final_redhat_00009.1.el8ea
0:1.3.1-8.Final_redhat_00009.1.el8ea
redhat/eap7-picketlink-bindings<0:2.5.5-23.SP12_redhat_00012.1.el8ea
0:2.5.5-23.SP12_redhat_00012.1.el8ea
redhat/eap7-stax2-api<0:4.2.0-1.redhat_00001.1.el8ea
0:4.2.0-1.redhat_00001.1.el8ea
redhat/eap7-sun-istack-commons<0:3.0.10-1.redhat_00001.1.el8ea
0:3.0.10-1.redhat_00001.1.el8ea
redhat/eap7-thrift<0:0.13.0-1.redhat_00002.1.el8ea
0:0.13.0-1.redhat_00002.1.el8ea
redhat/eap7-wildfly<0:7.2.7-4.GA_redhat_00004.1.el8ea
0:7.2.7-4.GA_redhat_00004.1.el8ea
redhat/eap7-wildfly-http-client<0:1.0.20-1.Final_redhat_00001.1.el8ea
0:1.0.20-1.Final_redhat_00001.1.el8ea
redhat/eap7-wildfly-openssl<0:1.0.9-2.SP03_redhat_00001.1.el8ea
0:1.0.9-2.SP03_redhat_00001.1.el8ea
redhat/eap7-wildfly-transaction-client<0:1.1.9-1.Final_redhat_00001.1.el8ea
0:1.1.9-1.Final_redhat_00001.1.el8ea
redhat/eap7-woodstox-core<0:6.0.3-1.redhat_00001.1.el8ea
0:6.0.3-1.redhat_00001.1.el8ea
redhat/eap7-xml-security<0:2.1.4-1.redhat_00001.1.el8ea
0:2.1.4-1.redhat_00001.1.el8ea
Netty Netty<4.1.44
Debian Debian Linux=8.0
Debian Debian Linux=9.0
Debian Debian Linux=10.0
Fedoraproject Fedora=33
Canonical Ubuntu Linux=18.04
redhat Jboss Amq Clients=2
redhat JBoss Enterprise Application Platform=7.2
redhat JBoss Enterprise Application Platform=7.3
redhat Enterprise Linux=6.0
redhat Enterprise Linux=7.0
redhat Enterprise Linux=8.0
All of the following
Any of the following
redhat Jboss Amq Clients=2
redhat JBoss Enterprise Application Platform=7.2
redhat JBoss Enterprise Application Platform=7.3
Any of the following
redhat Enterprise Linux=6.0
redhat Enterprise Linux=7.0
redhat Enterprise Linux=8.0
maven/io.netty:netty-codec-http<4.1.44
4.1.44
maven/io.netty:netty<4.0.0
maven/org.jboss.netty:netty<4.0.0
redhat/netty<4.1.44
4.1.44
IBM Data Virtualization on Cloud Pak for Data<=3.0
IBM Watson Query on Cloud Pak for Data<=2.2
IBM Watson Query on Cloud Pak for Data<=2.1
IBM Watson Query on Cloud Pak for Data<=2.0
IBM Data Virtualization on Cloud Pak for Data<=1.8
IBM Data Virtualization on Cloud Pak for Data<=1.7
debian/netty
1:4.1.48-4+deb11u21:4.1.48-7+deb12u11:4.1.48-101:4.1.48-16
Remediation
Patch Available
Information
* Use HTTP/2 instead (clear boundaries between requests)
* Disable reuse of backend connections eg. ```http-reuse never``` in HAProxy or whatever equivalent LB settings
Event History
Jan 29, 2020
CVE Published
12:00 AM
CVE Published
via MITRE·08:33 PM
Data Sourced
via MITRE·08:33 PM
Description
Data Sourced
via NVD·09:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Feb 5, 2020
Data Sourced
via Red Hat·02:39 PM
DescriptionSeverityAffected Software
Feb 21, 2020
Advisory Published
via GitHub·06:55 PM
Data Sourced
via GitHub·06:55 PM
DescriptionSeverityWeaknessAffected Software
Aug 15, 2025
Data Sourced
via IBM·03:29 PM
DescriptionAffected Software
Feb 23, 2026
Data Sourced
via Ubuntu·03:18 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Launchpad·03:19 PM
Description
Data Sourced
via Debian·03:19 PM
DescriptionAffected Software
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
1
What is the severity of CVE-2019-20444?
CVE-2019-20444 has been rated as a medium severity vulnerability due to the potential for HTTP smuggling attacks.
2
How do I fix CVE-2019-20444?
To fix CVE-2019-20444, update the affected Netty versions to 4.1.44 or later.
3
Which versions of Netty are affected by CVE-2019-20444?
CVE-2019-20444 affects Netty versions prior to 4.1.44.
4
What type of vulnerability is CVE-2019-20444?
CVE-2019-20444 is an HTTP smuggling vulnerability that can lead to header misinterpretation.
5
Is CVE-2019-20444 exploitable in production systems?
Yes, CVE-2019-20444 can be exploited in production systems if they use the affected versions of Netty.