CVE-2020-13943: Apache Tomcat Exposure Of Sensitive Information To Vulnerability

MODERATE
Advisory Identifier: GHSA-f268-65qc-98vg
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CVSS 4.3
CWE-200
Published
Advisory Summary

CVE-2020-13943 is a MODERATE (CVSS 4.3) exposure of sensitive information to vulnerability (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) affecting Apache Tomcat libraries in the Maven ecosystem. The issue involves exposure of sensitive information to an unauthorized actor in apache tomcat. Remediation is available by upgrading affected packages to version 10.0.0-M8, 9.0.38, 8.5.58.

CVE-2020-13943 at a Glance

CVE Identifier CVE-2020-13943
GHSA Identifier GHSA-f268-65qc-98vg
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Affected Product Apache Tomcat
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2020-13943

To remediate this vulnerability, upgrade all affected Apache Tomcat dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.apache.tomcat:tomcat-coyote fixed: 10.0.0-M8 
<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat-coyote</artifactId>
    <version>10.0.0-M8</version>
</dependency>
org.apache.tomcat:tomcat-coyote fixed: 9.0.38 
<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat-coyote</artifactId>
    <version>9.0.38</version>
</dependency>
org.apache.tomcat:tomcat-coyote fixed: 8.5.58 
<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat-coyote</artifactId>
    <version>8.5.58</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.apache.tomcat

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2020-13943, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.apache.tomcat

Analyze the terminal output to locate any version of Apache Tomcat in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 10.0.0-M8), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.apache.tomcat command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor, where the product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. In Apache Tomcat, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

If an HTTP/2 client connecting to Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37 or 8.5.0 to 8.5.57 exceeded the agreed maximum number of concurrent streams for a connection (in violation of the HTTP/2 protocol), it was possible that a subsequent request made on that connection could contain HTTP headers - including HTTP/2 pseudo headers - from a previous request rather than the intended headers. This could lead to users seeing responses for unexpected resources.

CVE-2020-13943 Affected Apache Tomcat Versions

3 component(s)
Fixed Versions:
10.0.0-M89.0.388.5.58
Product / Package Ecosystem Affected Versions Fixed Version
org.apache.tomcat:tomcat-coyote
maven/org.apache.tomcat/tomcat-coyote
Maven
≥ 10.0.0-M1
< 10.0.0-M8
10.0.0-M8
org.apache.tomcat:tomcat-coyote
maven/org.apache.tomcat/tomcat-coyote
Maven
≥ 9.0.0-M1
< 9.0.38
9.0.38
org.apache.tomcat:tomcat-coyote
maven/org.apache.tomcat/tomcat-coyote
Maven
≥ 8.5.0
< 8.5.58
8.5.58

References

NVD — CVE-2020-13943 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-13943
Security Fix Commit FIX COMMIT
https://github.com/apache/tomcat/commit/1bbc650cbc3f08d85a1ec6d803c47ae53a84f3bb
Security Fix Commit FIX COMMIT
https://github.com/apache/tomcat/commit/55911430df13f8c9998fbdee1f9716994d2db59b
Security Fix Commit FIX COMMIT
https://github.com/apache/tomcat/commit/9d7def063b47407a09a2f9202beed99f4dcb292a
lists.apache.org/thread.html/r4a3900... WEB
https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html
Apache Tomcat Security Information SECURITY
https://security.netapp.com/advisory/ntap-20201016-0007
Apache Tomcat Security Information SECURITY
https://www.debian.org/security/2021/dsa-4835
Apache Tomcat Security Information SECURITY
https://www.oracle.com/security-alerts/cpuApr2021.html
Apache Tomcat Security Information SECURITY
http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html
Apache Tomcat Security Information SECURITY
http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html

Frequently Asked Questions

What is CVE-2020-13943?
CVE-2020-13943 is a security vulnerability in Apache Tomcat involving Exposure of Sensitive Information to an Unauthorized Actor in Apache Tomcat under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.
Which Apache Tomcat versions are affected?
Affected versions include releases prior to 10.0.0-M8, 9.0.38, 8.5.58 across affected packages: org.apache.tomcat:tomcat-coyote.
What version fixes CVE-2020-13943?
Upgrading to 10.0.0-M8, 9.0.38, 8.5.58 (or the latest patched release for your respective branch) resolves the vulnerability.
Is tomcat-coyote affected?
Yes, org.apache.tomcat:tomcat-coyote is affected in releases prior to 10.0.0-M8, 9.0.38, 8.5.58. Upgrade your dependency to 10.0.0-M8, 9.0.38, 8.5.58 or later.
What is the CVSS score of CVE-2020-13943?
CVE-2020-13943 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2020-13943?
CVE-2020-13943 is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor (The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.).
How can I check Maven dependencies for CVE-2020-13943?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.apache.tomcat'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
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  "id" : "GHSA-f268-65qc-98vg",
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  "published" : "2022-02-09T23:03:53Z",
  "aliases" : [ "CVE-2020-13943" ],
  "summary" : "Exposure of Sensitive Information to an Unauthorized Actor in Apache Tomcat",
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    } ],
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  "references" : [ {
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    "type" : "WEB",
    "url" : "https://github.com/apache/tomcat/commit/55911430df13f8c9998fbdee1f9716994d2db59b"
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    "type" : "WEB",
    "url" : "https://github.com/apache/tomcat/commit/9d7def063b47407a09a2f9202beed99f4dcb292a"
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    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20201016-0007"
  }, {
    "type" : "WEB",
    "url" : "https://www.debian.org/security/2021/dsa-4835"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuApr2021.html"
  }, {
    "type" : "WEB",
    "url" : "http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html"
  }, {
    "type" : "WEB",
    "url" : "http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-12T18:12:07Z",
    "nvd_published_at" : "2020-10-12T14:15:00Z"
  }
}