Skip to content
Fencer Vulns
medium 4.8

CVE-2020-1935 json

Potential HTTP request smuggling in Apache Tomcat

published 2020-02-24 6 y ago modified 2026-10-08 31 d ago also BIT-tomcat-2020-1935 , EUVD-2020-0311 , GHSA-qxf4-chvg-4r8r

cvss
4.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
9.4%
EPSS 9.4% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

Summary

In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.

Patch / fix

  • maven org.apache.tomcat.embed:tomcat-embed-core 7.0.100, 8.5.51, 9.0.31
  • maven org.apache.tomcat:tomcat 7.0.100, 8.5.51, 9.0.31
  • bitnami tomcat 7.0.100, 8.5.51, 9.0.31
  • tomcat9 Debian 14, Debian 13, Debian 12 9.0.31-1

debian advisories DEBIAN-CVE-2020-1935

  • tomcat8 Ubuntu 16.04 LTS 8.0.32-1ubuntu1.13

ubuntu advisories UBUNTU-CVE-2020-1935

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

  • jss RHEL 8 4.7.3-1.module+el8.3.0+8058+d5cd4219
  • xsom RHEL 8 0-19.20110809svn.module+el8.1.0+3366+6dfb954c
  • slf4j RHEL 8 1.7.25-4.module+el8.1.0+3366+6dfb954c
  • pki-ca RHEL 8 10.9.4-1.module+el8.3.0+8058+d5cd4219
  • ldapjdk RHEL 8 4.22.0-1.module+el8.3.0+6784+6e1e4c62
  • pki-kra RHEL 8 10.9.4-1.module+el8.3.0+8058+d5cd4219
  • stax-ex RHEL 8 1.7.7-8.module+el8.2.0+5723+4574fbff
  • bea-stax RHEL 8 1.2.0-16.module+el8.1.0+3366+6dfb954c

red hat advisories RHSA-2020:4847RHSA-2021:1030RHSA-2021:0882RHSA-2020:1520RHSA-2020:3303RHSA-2020:5020

  • tomcat SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES 12 SP3-LTSS +8 more 8.0.53-29.37.1
  • tomcat SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +1 more 9.0.31-3.25.1
  • tomcat SLE Module for Web and Scripting 15 SP1 9.0.31-4.22.1
  • tomcat SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 9.0.31-3.42.2

suse advisories SUSE-SU-2020:2611-1SUSE-SU-2020:0632-1SUSE-SU-2020:0631-1SUSE-SU-2020:0598-1

  • tomcat openSUSE Tumbleweed 9.0.36-8.4
  • tomcat10 openSUSE Tumbleweed 10.1.14-1.1
  • tomcat openSUSE Leap 15.1 9.0.31-lp151.3.12.1

opensuse advisories openSUSE-SU-2024:11468-1openSUSE-SU-2024:13441-1openSUSE-SU-2020:0345-1

  • xsom Rocky Linux 8 0-19.20110809svn.module+el8.3.0+53+ea062990
  • slf4j Rocky Linux 8 1.7.25-4.module+el8.5.0+697+f586bb30
  • slf4j Rocky Linux 8 1.7.25-4.module+el8.3.0+74+855e3f5d
  • slf4j Rocky Linux 8 1.7.25-4.module+el8.3.0+133+b8b54b58
  • ldapjdk Rocky Linux 8 4.22.0-1.module+el8.4.0+418+b7ae1d4a
  • stax-ex Rocky Linux 8 1.7.7-8.module+el8.3.0+53+ea062990
  • bea-stax Rocky Linux 8 1.2.0-16.module+el8.3.0+53+ea062990
  • resteasy Rocky Linux 8 3.0.26-3.module+el8.3.0+53+ea062990

rocky linux advisories RLSA-2020:4847

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-2020-1935 updated cvss 4.3

tomcat: Mishandling of Transfer-Encoding header allows for HTTP request smuggling

  • Red Hat Enterprise Linux 5 tomcat5 Red Hat Enterprise Linux 6 tomcat6, tomcat6-lib, tomcat6-log4j, tomcat6-javadoc, tomcat6-webapps, tomcat6-el-2.1-api, +4 more Red Hat JBoss Enterprise Application Platform 6 jbossweb jbossweb Red Hat JBoss Fuse 6 tomcat Red Hat OpenStack Platform 10 (Newton) opendaylight
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenStack Platform 13 (Queens) opendaylight
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 8) jss 4.7.3-1.module+el8.3.0+8058+d5cd4219, slf4j 1.7.25-4.module+el8.1.0+3366+6dfb954c, pki-ca 10.9.4-1.module+el8.3.0+8058+d5cd4219, stax-ex 1.7.7-8.module+el8.2.0+5723+4574fbff, velocity 1.7-24.module+el8.1.0+3366+6dfb954c, ldapjdk 4.22.0-1.module+el8.3.0+6784+6e1e4c62, +44 more
    fixed: vendor fix RHSA-2020:4847
  • Red Hat Enterprise Linux Client (v. 7) tomcat 7.0.76-16.el7_9, tomcat-servlet-3.0-api 7.0.76-16.el7_9 Red Hat Enterprise Linux Client Optional (v. 7) tomcat 7.0.76-16.el7_9, tomcat-lib 7.0.76-16.el7_9, tomcat-jsvc 7.0.76-16.el7_9, tomcat-javadoc 7.0.76-16.el7_9, tomcat-webapps 7.0.76-16.el7_9, tomcat-el-2.2-api 7.0.76-16.el7_9, +3 more
    fixed: vendor fix RHSA-2020:5020
  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.6) tomcat 7.0.76-11.el7_6, tomcat-servlet-3.0-api 7.0.76-11.el7_6
    fixed: vendor fix RHSA-2021:0882
  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) tomcat 7.0.76-12.el7_7, tomcat-servlet-3.0-api 7.0.76-12.el7_7
    fixed: vendor fix RHSA-2021:1030
  • Red Hat Enterprise Linux ComputeNode Optional (v. 7) tomcat 7.0.76-16.el7_9, tomcat-lib 7.0.76-16.el7_9, tomcat-jsvc 7.0.76-16.el7_9, tomcat-javadoc 7.0.76-16.el7_9, tomcat-webapps 7.0.76-16.el7_9, tomcat-el-2.2-api 7.0.76-16.el7_9, +3 more
    fixed: vendor fix RHSA-2020:5020
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6) tomcat 7.0.76-11.el7_6, tomcat-lib 7.0.76-11.el7_6, tomcat-jsvc 7.0.76-11.el7_6, tomcat-javadoc 7.0.76-11.el7_6, tomcat-webapps 7.0.76-11.el7_6, tomcat-el-2.2-api 7.0.76-11.el7_6, +3 more
    fixed: vendor fix RHSA-2021:0882
show 16 more
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7) tomcat 7.0.76-12.el7_7, tomcat-lib 7.0.76-12.el7_7, tomcat-jsvc 7.0.76-12.el7_7, tomcat-javadoc 7.0.76-12.el7_7, tomcat-webapps 7.0.76-12.el7_7, tomcat-el-2.2-api 7.0.76-12.el7_7, +3 more
    fixed: vendor fix RHSA-2021:1030
  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) tomcat 7.0.76-11.el7_6, tomcat-lib 7.0.76-11.el7_6, tomcat-webapps 7.0.76-11.el7_6, tomcat-el-2.2-api 7.0.76-11.el7_6, tomcat-jsp-2.2-api 7.0.76-11.el7_6, tomcat-admin-webapps 7.0.76-11.el7_6, +1 more Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) tomcat 7.0.76-11.el7_6, tomcat-lib 7.0.76-11.el7_6, tomcat-jsvc 7.0.76-11.el7_6, tomcat-javadoc 7.0.76-11.el7_6, tomcat-webapps 7.0.76-11.el7_6, tomcat-el-2.2-api 7.0.76-11.el7_6, +3 more
    fixed: vendor fix RHSA-2021:0882
  • Red Hat Enterprise Linux Server (v. 7) tomcat 7.0.76-16.el7_9, tomcat-lib 7.0.76-16.el7_9, tomcat-webapps 7.0.76-16.el7_9, tomcat-el-2.2-api 7.0.76-16.el7_9, tomcat-jsp-2.2-api 7.0.76-16.el7_9, tomcat-admin-webapps 7.0.76-16.el7_9, +1 more
    fixed: vendor fix RHSA-2020:5020
  • Red Hat Enterprise Linux Server EUS (v. 7.6) tomcat 7.0.76-11.el7_6, tomcat-lib 7.0.76-11.el7_6, tomcat-webapps 7.0.76-11.el7_6, tomcat-el-2.2-api 7.0.76-11.el7_6, tomcat-jsp-2.2-api 7.0.76-11.el7_6, tomcat-admin-webapps 7.0.76-11.el7_6, +1 more
    fixed: vendor fix RHSA-2021:0882
  • Red Hat Enterprise Linux Server EUS (v. 7.7) tomcat 7.0.76-12.el7_7, tomcat-lib 7.0.76-12.el7_7, tomcat-webapps 7.0.76-12.el7_7, tomcat-el-2.2-api 7.0.76-12.el7_7, tomcat-jsp-2.2-api 7.0.76-12.el7_7, tomcat-admin-webapps 7.0.76-12.el7_7, +1 more
    fixed: vendor fix RHSA-2021:1030
  • Red Hat Enterprise Linux Server Optional (v. 7) tomcat 7.0.76-16.el7_9, tomcat-lib 7.0.76-16.el7_9, tomcat-jsvc 7.0.76-16.el7_9, tomcat-javadoc 7.0.76-16.el7_9, tomcat-webapps 7.0.76-16.el7_9, tomcat-el-2.2-api 7.0.76-16.el7_9, +3 more
    fixed: vendor fix RHSA-2020:5020
  • Red Hat Enterprise Linux Server Optional EUS (v. 7.6) tomcat 7.0.76-11.el7_6, tomcat-lib 7.0.76-11.el7_6, tomcat-jsvc 7.0.76-11.el7_6, tomcat-javadoc 7.0.76-11.el7_6, tomcat-webapps 7.0.76-11.el7_6, tomcat-el-2.2-api 7.0.76-11.el7_6, +3 more
    fixed: vendor fix RHSA-2021:0882
  • Red Hat Enterprise Linux Server Optional EUS (v. 7.7) tomcat 7.0.76-12.el7_7, tomcat-lib 7.0.76-12.el7_7, tomcat-jsvc 7.0.76-12.el7_7, tomcat-javadoc 7.0.76-12.el7_7, tomcat-webapps 7.0.76-12.el7_7, tomcat-el-2.2-api 7.0.76-12.el7_7, +3 more
    fixed: vendor fix RHSA-2021:1030
  • Red Hat Enterprise Linux Workstation (v. 7) tomcat 7.0.76-16.el7_9, tomcat-lib 7.0.76-16.el7_9, tomcat-webapps 7.0.76-16.el7_9, tomcat-el-2.2-api 7.0.76-16.el7_9, tomcat-jsp-2.2-api 7.0.76-16.el7_9, tomcat-admin-webapps 7.0.76-16.el7_9, +1 more Red Hat Enterprise Linux Workstation Optional (v. 7) tomcat-jsvc 7.0.76-16.el7_9, tomcat-javadoc 7.0.76-16.el7_9, tomcat-docs-webapp 7.0.76-16.el7_9
    fixed: vendor fix RHSA-2020:5020
  • Red Hat Fuse 7.9
    fixed: vendor fix RHSA-2021:3140
  • Red Hat JBoss Web Server (JWS) 5.3
    fixed: vendor fix RHSA-2020:1521
  • Red Hat JBoss Web Server 3.1
    fixed: vendor fix RHSA-2020:3305
  • Red Hat JBoss Web Server 3.1 for RHEL 6 tomcat7 7.0.70-41.ep7.el6, tomcat8 8.0.36-45.ep7.el6, tomcat7-lib 7.0.70-41.ep7.el6, tomcat8-lib 8.0.36-45.ep7.el6, tomcat7-jsvc 7.0.70-41.ep7.el6, tomcat8-jsvc 8.0.36-45.ep7.el6, +18 more Red Hat JBoss Web Server 3.1 for RHEL 7 tomcat7 7.0.70-41.ep7.el7, tomcat8 8.0.36-45.ep7.el7, tomcat7-lib 7.0.70-41.ep7.el7, tomcat8-lib 8.0.36-45.ep7.el7, tomcat7-jsvc 7.0.70-41.ep7.el7, tomcat8-jsvc 8.0.36-45.ep7.el7, +18 more
    fixed: vendor fix RHSA-2020:3303
  • Red Hat JBoss Web Server 5.3 for RHEL 6 Server jws5-tomcat 9.0.30-3.redhat_4.1.el6jws, jws5-tomcat-lib 9.0.30-3.redhat_4.1.el6jws, jws5-tomcat-native 1.2.23-4.redhat_4.el6jws, jws5-tomcat-javadoc 9.0.30-3.redhat_4.1.el6jws, jws5-tomcat-selinux 9.0.30-3.redhat_4.1.el6jws, jws5-tomcat-webapps 9.0.30-3.redhat_4.1.el6jws, +5 more Red Hat JBoss Web Server 5.3 for RHEL 7 Server jws5-tomcat 9.0.30-3.redhat_4.1.el7jws, jws5-tomcat-lib 9.0.30-3.redhat_4.1.el7jws, jws5-tomcat-native 1.2.23-4.redhat_4.el7jws, jws5-tomcat-javadoc 9.0.30-3.redhat_4.1.el7jws, jws5-tomcat-selinux 9.0.30-3.redhat_4.1.el7jws, jws5-tomcat-webapps 9.0.30-3.redhat_4.1.el7jws, +5 more Red Hat JBoss Web Server 5.3 for RHEL 8 jws5-tomcat 9.0.30-3.redhat_4.1.el8jws, jws5-tomcat-lib 9.0.30-3.redhat_4.1.el8jws, jws5-tomcat-native 1.2.23-4.redhat_4.el8jws, jws5-tomcat-javadoc 9.0.30-3.redhat_4.1.el8jws, jws5-tomcat-selinux 9.0.30-3.redhat_4.1.el8jws, jws5-tomcat-webapps 9.0.30-3.redhat_4.1.el8jws, +5 more
    fixed: vendor fix RHSA-2020:1520
  • Red Hat Runtimes Spring Boot 2.1.13
    fixed: vendor fix RHSA-2020:2367
  • Red Hat Decision Manager 7 tomcat Red Hat Process Automation 7 tomcat
    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

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
31 d ago

Exploit prediction

9.39% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
GitHub 3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
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
OSV 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 org.apache.tomcat.embed:tomcat-embed-core
<7.0.100
>=8.0.0, <8.5.51
>=9.0.0, <9.0.31
7.0.100
8.5.51
9.0.31
maven org.apache.tomcat:tomcat
<7.0.100
>=8.0.0, <8.5.51
>=9.0.0, <9.0.31
7.0.100
8.5.51
9.0.31
bitnami tomcat
>=7.0.0, <7.0.100
>=8.5.0, <8.5.51
>=9.0.0, <9.0.31
7.0.100
8.5.51
9.0.31

Affected products

  • Apache Apache Tomcat

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.