CVE-2021-42340: Apache Tomcat Remote Code Execution Vulnerability

Q: What is CVE-2021-42340?

CVE-2021-42340 is a security vulnerability in Apache Tomcat involving Missing Release of Resource after Effective Lifetime in Apache Tomcat under CWE-772: Missing Release of Resource after Effective Lifetime.

Q: Which Apache Tomcat versions are affected?

Affected versions include releases prior to 10.1.0-M6, 10.0.12, 9.0.54, 8.5.72 across affected packages: org.apache.tomcat:tomcat.

Q: What version fixes CVE-2021-42340?

Upgrading to 10.1.0-M6, 10.0.12, 9.0.54, 8.5.72 (or the latest patched release for your respective branch) resolves the vulnerability.

Q: Is tomcat affected?

Yes, org.apache.tomcat:tomcat is affected in releases prior to 10.1.0-M6, 10.0.12, 9.0.54, 8.5.72. Upgrade your dependency to 10.1.0-M6, 10.0.12, 9.0.54, 8.5.72 or later.

Q: What is the CVSS score of CVE-2021-42340?

CVE-2021-42340 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Q: What CWE is associated with CVE-2021-42340?

CVE-2021-42340 is classified under CWE-772: Missing Release of Resource after Effective Lifetime (The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.).

Q: How can I check Maven dependencies for CVE-2021-42340?

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.

HIGH

Advisory Identifier: GHSA-wph7-x527-w3h5

CVSS 7.5

CWE-772

Published 2021-10-15

Advisory Summary

CVE-2021-42340 is a HIGH (CVSS 7.5) remote code execution vulnerability (CWE-772: Missing Release of Resource after Effective Lifetime) affecting Apache Tomcat libraries in the Maven ecosystem. The issue involves missing release of resource after effective lifetime in apache tomcat. Remediation is available by upgrading affected packages to version 10.1.0-M6, 10.0.12, 9.0.54, 8.5.72.

CVE-2021-42340 at a Glance

CVE Identifier CVE-2021-42340

GHSA Identifier GHSA-wph7-x527-w3h5

Severity HIGH

CVSS v3.1 Base Score 7.5

CWE Classification CWE-772: Missing Release of Resource after Effective Lifetime

Affected Product Apache Tomcat

Package Ecosystem Maven

Published Date 2021-10-15

Last Updated 2024-03-11

Security Impact

CVSS: 7.5

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

Attack Vector Network (AV:N)

Attack Complexity Low (AC:L)

Privileges Required None (PR:N)

User Interaction None (UI:N)

Scope Unchanged (S:U)

Confidentiality None (C:N)

Integrity None (I:N)

Availability High (A:H)

How to Fix CVE-2021-42340

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 fixed: 10.1.0-M6

<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat</artifactId>
    <version>10.1.0-M6</version>
</dependency>

org.apache.tomcat:tomcat fixed: 10.0.12

<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat</artifactId>
    <version>10.0.12</version>
</dependency>

org.apache.tomcat:tomcat fixed: 9.0.54

<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat</artifactId>
    <version>9.0.54</version>
</dependency>

org.apache.tomcat:tomcat fixed: 8.5.72

<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat</artifactId>
    <version>8.5.72</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-2021-42340, 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 10.1.0-M6), 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-772: Missing Release of Resource after Effective Lifetime, where the product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed. 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

The fix for bug 63362 present in Apache Tomcat 10.1.0-M1 to 10.1.0-M5, 10.0.0-M1 to 10.0.11, 9.0.40 to 9.0.53 and 8.5.60 to 8.5.71 introduced a memory leak. The object introduced to collect metrics for HTTP upgrade connections was not released for WebSocket connections once the connection was closed. This created a memory leak that, over time, could lead to a denial of service via an OutOfMemoryError.

CVE-2021-42340 Affected Apache Tomcat Versions

4 component(s)

Fixed Versions:

10.1.0-M610.0.129.0.548.5.72

Product / Package	Ecosystem	Affected Versions	Fixed Version
org.apache.tomcat:tomcat maven/org.apache.tomcat/tomcat	Maven	≥ 10.1.0-M1 < 10.1.0-M6	10.1.0-M6
org.apache.tomcat:tomcat maven/org.apache.tomcat/tomcat	Maven	≥ 10.0.0-M1 < 10.0.12	10.0.12
org.apache.tomcat:tomcat maven/org.apache.tomcat/tomcat	Maven	≥ 9.0.40 < 9.0.54	9.0.54
org.apache.tomcat:tomcat maven/org.apache.tomcat/tomcat	Maven	≥ 8.5.60 < 8.5.72	8.5.72

References

NVD — CVE-2021-42340 NVD

https://nvd.nist.gov/vuln/detail/CVE-2021-42340

Security Fix Commit FIX COMMIT

https://github.com/apache/tomcat/commit/31d62426645824bdfe076a0c0eafa904d90b4fb9

Security Fix Commit FIX COMMIT

https://github.com/apache/tomcat/commit/80f1438ec45e77a07b96419808971838d259eb47

Security Fix Commit FIX COMMIT

https://github.com/apache/tomcat/commit/d27535bdee95d252418201eb21e9d29476aa6b6a

Security Fix Commit FIX COMMIT

https://github.com/apache/tomcat/commit/d5a6660cba7f51589468937bf3bbad4db7810371

Apache Tomcat Security Information SECURITY

https://www.oracle.com/security-alerts/cpujul2022.html

Apache Tomcat Security Information SECURITY

https://www.oracle.com/security-alerts/cpujan2022.html

Apache Tomcat Security Information SECURITY

https://www.oracle.com/security-alerts/cpuapr2022.html

Apache Tomcat Security Information SECURITY

https://www.debian.org/security/2021/dsa-5009

Apache Tomcat Security Information SECURITY

https://tomcat.apache.org/security-9.html

Apache Tomcat Security Information SECURITY

https://tomcat.apache.org/security-8.html

Apache Tomcat Security Information SECURITY

https://tomcat.apache.org/security-10.html

Apache Tomcat Security Information SECURITY

https://security.netapp.com/advisory/ntap-20211104-0001

Apache Tomcat Security Information SECURITY

https://security.gentoo.org/glsa/202208-34

lists.apache.org/thread.html/r83a35b... WEB

https://lists.apache.org/thread.html/r83a35be60f06aca2065f188ee542b9099695d57ced2e70e0885f905c%40%3Cannounce.tomcat.apache.org%3E

lists.apache.org/thread.html/r8097a2... WEB

https://lists.apache.org/thread.html/r8097a2d1550aa78e585fc77e602b9046e6d4099d8d132497c5387784@%3Ccommits.myfaces.apache.org%3E

kc.mcafee.com/corporate/index WEB

https://kc.mcafee.com/corporate/index?page=content&id=SB10379

Apache Tomcat Source Repository REPOSITORY

https://github.com/apache/tomcat

Frequently Asked Questions

What is CVE-2021-42340?

CVE-2021-42340 is a security vulnerability in Apache Tomcat involving Missing Release of Resource after Effective Lifetime in Apache Tomcat under CWE-772: Missing Release of Resource after Effective Lifetime.

Which Apache Tomcat versions are affected?

Affected versions include releases prior to 10.1.0-M6, 10.0.12, 9.0.54, 8.5.72 across affected packages: org.apache.tomcat:tomcat.

What version fixes CVE-2021-42340?

Upgrading to 10.1.0-M6, 10.0.12, 9.0.54, 8.5.72 (or the latest patched release for your respective branch) resolves the vulnerability.

Is tomcat affected?

Yes, org.apache.tomcat:tomcat is affected in releases prior to 10.1.0-M6, 10.0.12, 9.0.54, 8.5.72. Upgrade your dependency to 10.1.0-M6, 10.0.12, 9.0.54, 8.5.72 or later.

What is the CVSS score of CVE-2021-42340?

CVE-2021-42340 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

What CWE is associated with CVE-2021-42340?

CVE-2021-42340 is classified under CWE-772: Missing Release of Resource after Effective Lifetime (The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.).

How can I check Maven dependencies for CVE-2021-42340?

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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  "aliases" : [ "CVE-2021-42340" ],
  "summary" : "Missing Release of Resource after Effective Lifetime in Apache Tomcat",
  "details" : "The fix for bug 63362 present in Apache Tomcat 10.1.0-M1 to 10.1.0-M5, 10.0.0-M1 to 10.0.11, 9.0.40 to 9.0.53 and 8.5.60 to 8.5.71 introduced a memory leak. The object introduced to collect metrics for HTTP upgrade connections was not released for WebSocket connections once the connection was closed. This created a memory leak that, over time, could lead to a denial of service via an OutOfMemoryError.",
  "severity" : [ {
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  } ],
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      } ]
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    "database_specific" : {
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    "url" : "https://github.com/apache/tomcat/commit/d27535bdee95d252418201eb21e9d29476aa6b6a"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/apache/tomcat/commit/d5a6660cba7f51589468937bf3bbad4db7810371"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujul2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujan2022.html"
  }, {
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    "url" : "https://www.oracle.com/security-alerts/cpuapr2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.debian.org/security/2021/dsa-5009"
  }, {
    "type" : "WEB",
    "url" : "https://tomcat.apache.org/security-9.html"
  }, {
    "type" : "WEB",
    "url" : "https://tomcat.apache.org/security-8.html"
  }, {
    "type" : "WEB",
    "url" : "https://tomcat.apache.org/security-10.html"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20211104-0001"
  }, {
    "type" : "WEB",
    "url" : "https://security.gentoo.org/glsa/202208-34"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/r83a35be60f06aca2065f188ee542b9099695d57ced2e70e0885f905c%40%3Cannounce.tomcat.apache.org%3E"
  }, {
    "type" : "WEB",
    "url" : "https://lists.apache.org/thread.html/r8097a2d1550aa78e585fc77e602b9046e6d4099d8d132497c5387784@%3Ccommits.myfaces.apache.org%3E"
  }, {
    "type" : "WEB",
    "url" : "https://kc.mcafee.com/corporate/index?page=content&id=SB10379"
  }, {
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  } ],
  "database_specific" : {
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    "nvd_published_at" : "2021-10-14T20:15:00Z"
  }
}

CVSS V3

7.5 HIGH

Attack Vector Network (AV:N)

Attack Complexity Low (AC:L)

Privileges Required None (PR:N)

User Interaction None (UI:N)

Scope Unchanged (S:U)

Confidentiality None (C:N)

Integrity None (I:N)

Availability High (A:H)

Vector String

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Advisory Metadata

Source ID: GHSA-wph7-x527-w3h5
Schema Version: 1.4.0
Published: 2021-10-15 18:51
Last Modified: 2024-03-11 16:36
Database Record File: advisories/github-reviewed/2021/10/GHSA-wph7-x527-w3h5/GHSA-wph7-x527-w3h5.json