CVE-2020-17527: Apache Tomcat: Request header mix-up between HTTP/2 streams

Published Dec 3, 2020
·
Updated

Apache Tomcat could allow a remote attacker to obtain sensitive information, caused by an issue when the HTTP request header value can be reused from the previous stream received on an HTTP/2 connection. By sending a specially-crafted HTTP request, an attacker could exploit this vulnerability to obtain sensitive information, and use this information to launch further attacks against the affected system.

Other sources

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

— Microsoft

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.

While investigating Bug 64830 it was discovered that Apache Tomcat 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.

Reference: https://lists.apache.org/thread.html/rce5ac9a40173651d540babce59f6f3825f12c6d4e886ba00823b11e5@%3Cannounce.apache.org%3E

— Red Hat

Affected Software

70 affected componentsFixes available
redhat/jws5-tomcat<0:9.0.36-9.redhat_8.1.el7
0:9.0.36-9.redhat_8.1.el7
redhat/jws5-tomcat-native<0:1.2.25-3.redhat_3.el7
0:1.2.25-3.redhat_3.el7
redhat/jws5-tomcat<0:9.0.36-9.redhat_8.1.el8
0:9.0.36-9.redhat_8.1.el8
redhat/jws5-tomcat-native<0:1.2.25-3.redhat_3.el8
0:1.2.25-3.redhat_3.el8
maven/org.apache.tomcat:tomcat-coyote>=8.5.0<8.5.60
8.5.60
maven/org.apache.tomcat:tomcat-coyote>=9.0.0-M1<9.0.40
9.0.40
maven/org.apache.tomcat:tomcat-coyote>=10.0.0-M1<10.0.0-M10
10.0.0-M10
IBM IBM® Engineering Requirements Management DOORS<=9.7.2.7
IBM IBM® Engineering Requirements Management DOORS Web Access<=9.7.2.7
Apache Tomcat>=8.5.1<=8.5.59
Apache Tomcat>=9.0.1<=9.0.35
Apache Tomcat=9.0.0-milestone10
Apache Tomcat=9.0.0-milestone11
Apache Tomcat=9.0.0-milestone12
Apache Tomcat=9.0.0-milestone13
Apache Tomcat=9.0.0-milestone14
Apache Tomcat=9.0.0-milestone15
Apache Tomcat=9.0.0-milestone16
Apache Tomcat=9.0.0-milestone17
Apache Tomcat=9.0.0-milestone18
Apache Tomcat=9.0.0-milestone19
Apache Tomcat=9.0.0-milestone20
Apache Tomcat=9.0.0-milestone21
Apache Tomcat=9.0.0-milestone22
Apache Tomcat=9.0.0-milestone23
Apache Tomcat=9.0.0-milestone24
Apache Tomcat=9.0.0-milestone25
Apache Tomcat=9.0.0-milestone26
Apache Tomcat=9.0.0-milestone27
Apache Tomcat=9.0.0-milestone5
Apache Tomcat=9.0.0-milestone6
Apache Tomcat=9.0.0-milestone7
Apache Tomcat=9.0.0-milestone8
Apache Tomcat=9.0.0-milestone9
Apache Tomcat=9.0.35-3.39.1
Apache Tomcat=9.0.35-3.57.3
Apache Tomcat=9.0.36
Apache Tomcat=9.0.37
Apache Tomcat=9.0.38
Apache Tomcat=9.0.39
Apache Tomcat=10.0.0-milestone1
Apache Tomcat=10.0.0-milestone2
Apache Tomcat=10.0.0-milestone3
Apache Tomcat=10.0.0-milestone4
Apache Tomcat=10.0.0-milestone5
Apache Tomcat=10.0.0-milestone6
Apache Tomcat=10.0.0-milestone7
Apache Tomcat=10.0.0-milestone8
Apache Tomcat=10.0.0-milestone9
NetApp Element Plug-in Vcenter Server
NetApp OnCommand System Manager>=3.0.0<=3.1.3
Debian Debian Linux=9.0
Debian Debian Linux=10.0
Oracle Blockchain Platform<21.1.2
Oracle Communications Cloud Native Core Binding Support Function=1.10.0
Oracle Communications Cloud Native Core Policy=1.14.0
Oracle Communications Instant Messaging Server=10.0.1.5.0
Oracle Instantis Enterprisetrack=17.1
Oracle Instantis Enterprisetrack=17.2
Oracle Instantis Enterprisetrack=17.3
Oracle MySQL Enterprise Monitor<8.0.23
Oracle SD-WAN Edge=9.0
Oracle Workload Manager=18c
Oracle Workload Manager=19c
debian/tomcat9
9.0.43-2~deb11u109.0.43-2~deb11u129.0.70-29.0.95-1
redhat/tomcat<10.0.0
10.0.0
redhat/tomcat<9.0.40
9.0.40
redhat/tomcat<8.5.60
8.5.60
Microsoft cbl2 tomcat 9.0.39-5
Patch available
Microsoft cbl2 tomcat 9.0.39-6
Patch available

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/jws5-tomcat to a version that resolves this vulnerability.

    Fixed in 0:9.0.36-9.redhat_8.1.el7
  2. Upgrade

    Upgrade redhat/jws5-tomcat-native to a version that resolves this vulnerability.

    Fixed in 0:1.2.25-3.redhat_3.el7
  3. Upgrade

    Upgrade redhat/jws5-tomcat to a version that resolves this vulnerability.

    Fixed in 0:9.0.36-9.redhat_8.1.el8
  4. Upgrade

    Upgrade redhat/jws5-tomcat-native to a version that resolves this vulnerability.

    Fixed in 0:1.2.25-3.redhat_3.el8
  5. Upgrade

    Upgrade maven/org.apache.tomcat:tomcat-coyote to a version that resolves this vulnerability.

    Fixed in 8.5.60
  6. Upgrade

    Upgrade maven/org.apache.tomcat:tomcat-coyote to a version that resolves this vulnerability.

    Fixed in 9.0.40
  7. Upgrade

    Upgrade maven/org.apache.tomcat:tomcat-coyote to a version that resolves this vulnerability.

    Fixed in 10.0.0-M10
  8. Upgrade

    Upgrade debian/tomcat9 to a version that resolves this vulnerability.

    Fixed in 9.0.43-2~deb11u10Fixed in 9.0.43-2~deb11u12Fixed in 9.0.70-2Fixed in 9.0.95-1
  9. Upgrade

    Upgrade redhat/tomcat to a version that resolves this vulnerability.

    Fixed in 10.0.0
  10. Upgrade

    Upgrade redhat/tomcat to a version that resolves this vulnerability.

    Fixed in 9.0.40
  11. Upgrade

    Upgrade redhat/tomcat to a version that resolves this vulnerability.

    Fixed in 8.5.60

Event History

Dec 3, 2020
CVE Published
12:00 AM
CVE Published
via MITRE·06:30 PM
Data Sourced
via MITRE·06:30 PM
DescriptionWeakness
Data Sourced
via NVD·07:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·08:38 PM
DescriptionSeverityAffected Software
Feb 9, 2022
Advisory Published
via GitHub·10:58 PM
Jan 11, 2024
Data Sourced
via Launchpad·11:44 PM
Description
Sep 16, 2024
Data Sourced
via Ubuntu·02:24 AM
RemedyDescriptionSeverityAffected Software
Oct 1, 2025
Data Sourced
via Microsoft·11:11 PM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

What is the severity of CVE-2020-17527?

The severity of CVE-2020-17527 is high.

2

How does CVE-2020-17527 affect Apache Tomcat?

CVE-2020-17527 affects Apache Tomcat versions 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.

3

How can I fix CVE-2020-17527 in Apache Tomcat?

To fix CVE-2020-17527 in Apache Tomcat, update to version 10.0.0-M10, 9.0.40, or 8.5.60.

4

Are there any references for CVE-2020-17527?

Yes, you can find references for CVE-2020-17527 at the following links: [reference 1](https://www.cve.org/CVERecord?id=CVE-2020-17527), [reference 2](https://nvd.nist.gov/vuln/detail/CVE-2020-17527), [reference 3](http://tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.0.0-M10), [reference 4](http://tomcat.apache.org/security-8.html#Fixed_in_Apache_Tomcat_8.5.60), [reference 5](http://tomcat.apache.org/security-9.html#Fixed_in_Apache_Tomcat_9.0.40), [reference 6](https://bugzilla.redhat.com/show_bug.cgi?id=1904221), [reference 7](https://access.redhat.com/errata/RHSA-2021:5134).

5

What is the Common Weakness Enumeration (CWE) ID for CVE-2020-17527?

The Common Weakness Enumeration (CWE) ID for CVE-2020-17527 is 200.

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