Skip to content
Fencer Intel
high 7.5

CVE-2020-17527 in the critical feed json

Apache Tomcat: Request header mix-up between HTTP/2 streams

published 5y ago modified last mo. also BIT-tomcat-2020-17527 , EUVD-2022-1215 , GHSA-vvw4-rfwf-p6hx

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
24.6%
EPSS 24.6% chance of exploitation in 30 days, percentile 97%
public exploits
0
none known

Summary

While investigating bug 64830 it was discovered that Apache Tomcat 10.0.0-M1 to 10.0.0-M9, 9.0.0-M1 to 9.0.39 and 8.5.0 to 8.5.59 could re-use an HTTP request header value from the previous stream received on an HTTP/2 connection for the request associated with the subsequent stream. While this would most likely lead to an error and the closure of the HTTP/2 connection, it is possible that information could leak between requests.

Patch / fix

  • maven org.apache.tomcat:tomcat-coyote 8.5.60, 9.0.40, 10.0.0-M10
  • bitnami tomcat 8.5.60, 9.0.40
  • oracle blockchain_platform 21.1.2
  • oracle mysql_enterprise_monitor 8.0.23
  • tomcat9 Debian 14, Debian 13, Debian 12 9.0.40-1

debian advisories DEBIAN-CVE-2020-17527

  • tomcat9 Ubuntu 18.04 LTS 9.0.16-3ubuntu0.18.04.2
  • tomcat9 Ubuntu 20.04 LTS 9.0.31-1ubuntu0.2

ubuntu advisories UBUNTU-CVE-2020-17527

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 5.4 9.0.36-9.redhat_8.1.el7jws
  • jws5-tomcat jboss enterprise web server 5.4 9.0.36-9.redhat_8.1.el8jws
  • jws5-tomcat-lib jboss enterprise web server 5.4 9.0.36-9.redhat_8.1.el7jws
  • jws5-tomcat-lib jboss enterprise web server 5.4 9.0.36-9.redhat_8.1.el8jws
  • jws5-tomcat-native jboss enterprise web server 5.4 1.2.25-3.redhat_3.el7jws
  • jws5-tomcat-native jboss enterprise web server 5.4 1.2.25-3.redhat_3.el8jws
  • jws5-tomcat-javadoc jboss enterprise web server 5.4 9.0.36-9.redhat_8.1.el7jws
  • jws5-tomcat-javadoc jboss enterprise web server 5.4 9.0.36-9.redhat_8.1.el8jws

red hat advisories RHSA-2021:0494

  • tomcat SLE Module for Web and Scripting 15 SP1 9.0.36-4.53.1
  • tomcat SLE Module for Web and Scripting 15 SP2 9.0.36-3.18.1
  • tomcat SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 9.0.36-3.74.1
  • tomcat SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +3 more 9.0.36-3.58.1
  • 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-2021:0042-1SUSE-SU-2021:0041-1SUSE-SU-2021:0040-1SUSE-SU-2021:0031-1

  • tomcat openSUSE Tumbleweed 9.0.36-8.4
  • tomcat10 openSUSE Tumbleweed 10.1.14-1.1
  • tomcat openSUSE Leap 15.1 9.0.36-lp151.3.39.1
  • tomcat openSUSE Leap 15.2 9.0.36-lp152.2.16.1

opensuse advisories openSUSE-SU-2024:11468-1openSUSE-SU-2024:13441-1openSUSE-SU-2021:0081-1openSUSE-SU-2021:0043-1

  • tomcat9 Arch Linux 9.0.40-1

arch linux advisories AVG-1317

Is CVE-2020-17527 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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-2020-17527 updated cvss 7.5

tomcat: HTTP/2 request header mix-up

  • 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
    affected: no fix planned “Out of support scope”
  • Red Hat Fuse 7.10
    fixed: vendor fix RHSA-2021:5134
  • Red Hat JBoss Web Server 5
    fixed: vendor fix RHSA-2021:0495
  • Red Hat JBoss Web Server 5.4 for RHEL 7 Server jws5-tomcat 9.0.36-9.redhat_8.1.el7jws, jws5-tomcat-lib 9.0.36-9.redhat_8.1.el7jws, jws5-tomcat-native 1.2.25-3.redhat_3.el7jws, jws5-tomcat-javadoc 9.0.36-9.redhat_8.1.el7jws, jws5-tomcat-selinux 9.0.36-9.redhat_8.1.el7jws, jws5-tomcat-webapps 9.0.36-9.redhat_8.1.el7jws, +5 more Red Hat JBoss Web Server 5.4 for RHEL 8 jws5-tomcat 9.0.36-9.redhat_8.1.el8jws, jws5-tomcat-lib 9.0.36-9.redhat_8.1.el8jws, jws5-tomcat-native 1.2.25-3.redhat_3.el8jws, jws5-tomcat-javadoc 9.0.36-9.redhat_8.1.el8jws, jws5-tomcat-selinux 9.0.36-9.redhat_8.1.el8jws, jws5-tomcat-webapps 9.0.36-9.redhat_8.1.el8jws, +5 more
    fixed: vendor fix RHSA-2021:0494
  • Red Hat Support for Spring Boot 2.4.9
    fixed: vendor fix RHSA-2021:4012
  • Red Hat Decision Manager 7 tomcat 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 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
    +3 more products
    Red Hat OpenStack Platform 10 (Newton) opendaylight Red Hat OpenStack Platform 13 (Queens) opendaylight 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
last mo.

Exploit prediction

24.62% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-09).

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:H/I:N/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
maven org.apache.tomcat:tomcat-coyote
>=10.0.0-M1, <10.0.0-M10
>=9.0.0-M1, <9.0.40
>=8.5.0, <8.5.60
10.0.0-M10
9.0.40
8.5.60
bitnami tomcat
>=8.5.1, <8.5.60
>=9.0.1, <9.0.40
8.5.60
9.0.40

Affected products

  • Apache Software Foundation Apache Tomcat

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Intel 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.