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Fencer Vulns
high 7.5

CVE-2020-13934 in the critical feed json

Improper Restriction of Operations within the Bounds of a Memory Buffer in Apache Tomcat

published 2020-07-14 6 y ago modified 2026-10-08 31 d ago also BIT-tomcat-2020-13934 , EUVD-2022-1201 , GHSA-vf77-8h7g-gghp

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
64.1%
EPSS 64.1% chance of exploitation in 30 days, percentile 99.2%
public exploits
0
none known

Summary

An h2c direct connection to Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M5 to 9.0.36 and 8.5.1 to 8.5.56 did not release the HTTP/1.1 processor after the upgrade to HTTP/2. If a sufficient number of such requests were made, an OutOfMemoryException could occur leading to a denial of service.

Patch / fix

  • maven org.apache.tomcat:tomcat 8.5.56, 9.0.36, 10.0.0-M6
  • maven org.apache.tomcat:tomcat-coyote 8.5.56, 9.0.36, 10.0.0-M6
  • bitnami tomcat 8.5.57, 9.0.37
  • tomcat9 Debian 14, Debian 13, Debian 12 9.0.37-1

debian advisories DEBIAN-CVE-2020-13934

  • tomcat9 Ubuntu 20.04 LTS 9.0.31-1ubuntu0.1

ubuntu advisories UBUNTU-CVE-2020-13934

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

  • jws5-tomcat jboss enterprise web server 5.3 9.0.30-5.redhat_6.1.el6jws
  • jws5-tomcat jboss enterprise web server 5.3 9.0.30-5.redhat_6.1.el7jws
  • jws5-tomcat jboss enterprise web server 5.3 9.0.30-5.redhat_6.1.el8jws
  • jws5-tomcat-lib jboss enterprise web server 5.3 9.0.30-5.redhat_6.1.el6jws
  • jws5-tomcat-lib jboss enterprise web server 5.3 9.0.30-5.redhat_6.1.el7jws
  • jws5-tomcat-lib jboss enterprise web server 5.3 9.0.30-5.redhat_6.1.el8jws
  • jws5-tomcat-javadoc jboss enterprise web server 5.3 9.0.30-5.redhat_6.1.el6jws
  • jws5-tomcat-javadoc jboss enterprise web server 5.3 9.0.30-5.redhat_6.1.el7jws

red hat advisories RHSA-2020:3306

  • tomcat SLE Module for Web and Scripting 15 SP2 9.0.36-3.6.1
  • tomcat SLE Module for Web and Scripting 15 SP1 9.0.36-4.41.2
  • tomcat SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 9.0.36-3.65.2
  • tomcat SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +3 more 9.0.36-3.45.1
  • tomcat SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 9.0.115-3.160.1

suse advisories SUSE-SU-2026:1058-1SUSE-SU-2020:2047-1SUSE-SU-2020:2046-1SUSE-SU-2020:2045-1SUSE-SU-2020:2037-1

  • tomcat openSUSE Tumbleweed 9.0.43-8.1
  • tomcat10 openSUSE Tumbleweed 10.1.14-1.1
  • tomcat openSUSE Leap 15.2 9.0.36-lp152.2.4.1
  • tomcat openSUSE Leap 15.1 9.0.36-lp151.3.27.1

opensuse advisories openSUSE-SU-2024:12103-1openSUSE-SU-2024:13441-1openSUSE-SU-2020:1111-1openSUSE-SU-2020:1102-1

  • tomcat9 Arch Linux 9.0.37-1

arch linux advisories AVG-1205

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-2020-13934 updated cvss 7.5

tomcat: OutOfMemoryException caused by HTTP/2 connection leak could lead to DoS

  • Red Hat Enterprise Linux 8 pki-servlet-engine, pki-servlet-4.0-api
    affected: no fix available “Fix deferred”
  • Red Hat JBoss Data Grid 6 jbossweb jbossweb Red Hat JBoss Data Virtualization 6 jbossweb jbossweb Red Hat JBoss Enterprise Application Platform 6 jbossweb jbossweb Red Hat JBoss Fuse 6 tomcat Red Hat OpenStack Platform 10 (Newton) opendaylight
    affected: no fix planned “Out of support scope”
  • Red Hat Fuse 7.9
    fixed: vendor fix RHSA-2021:3140
  • Red Hat JBoss Web Server (JWS) 5.3
    fixed: vendor fix RHSA-2020:3308
  • Red Hat JBoss Web Server 5.3 for RHEL 6 Server jws5-tomcat 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-lib 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-javadoc 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-selinux 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-webapps 9.0.30-5.redhat_6.1.el6jws, jws5-tomcat-el-3.0-api 9.0.30-5.redhat_6.1.el6jws, +4 more Red Hat JBoss Web Server 5.3 for RHEL 7 Server jws5-tomcat 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-lib 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-javadoc 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-selinux 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-webapps 9.0.30-5.redhat_6.1.el7jws, jws5-tomcat-el-3.0-api 9.0.30-5.redhat_6.1.el7jws, +4 more Red Hat JBoss Web Server 5.3 for RHEL 8 jws5-tomcat 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-lib 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-javadoc 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-selinux 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-webapps 9.0.30-5.redhat_6.1.el8jws, jws5-tomcat-el-3.0-api 9.0.30-5.redhat_6.1.el8jws, +4 more
    fixed: vendor fix RHSA-2020:3306
  • Red Hat Runtimes Spring Boot 2.2.6
    fixed: vendor fix RHSA-2020:3806
  • Red Hat Decision Manager 7 tomcat Red Hat Enterprise Linux 6 tomcat6, tomcat6-lib, tomcat6-log4j, tomcat6-javadoc, tomcat6-webapps, tomcat6-el-2.1-api, +4 more Red Hat Enterprise Linux 7 tomcat, tomcat-lib, tomcat-jsvc, tomcat-javadoc, tomcat-webapps, tomcat-el-2.2-api, +4 more Red Hat Enterprise Linux 9 tomcat, tomcat-lib, tomcat-webapps, tomcat-el-3.0-api, tomcat-docs-webapp, tomcat-jsp-2.3-api, +2 more Red Hat JBoss Web Server 3 tomcat Red Hat OpenStack Platform 13 (Queens) opendaylight
    +2 more products
    Red Hat Process Automation 7 tomcat Red Hat Software Collections rh-java-common-tomcat-lib, rh-java-common-tomcat-javadoc, rh-java-common-tomcat-el-2.2-api, rh-java-common-tomcat-jsp-2.2-api, rh-java-common-tomcat-servlet-3.0-api
    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

64.12% chance of exploitation in the next 30 days, higher than 99.2% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven org.apache.tomcat:tomcat
>=10.0.0-M1, <10.0.0-M6
>=9.0.0.M5, <9.0.36
>=8.5.1, <8.5.56
10.0.0-M6
9.0.36
8.5.56
maven org.apache.tomcat:tomcat-coyote
>=10.0.0-M1, <10.0.0-M6
>=9.0.0.M5, <9.0.36
>=8.5.1, <8.5.56
10.0.0-M6
9.0.36
8.5.56
bitnami tomcat
>=8.5.1, <8.5.57
>=9.0.1, <9.0.37
8.5.57
9.0.37

Affected products

  • n/a Apache Tomcat

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-476 NULL Pointer Dereference
  • CWE-401 Missing Release of Memory after Effective Lifetime

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.