CVE-2021-21621: Support core Support Bundles Can Include User Vulnerability

LOW
Advisory Identifier: GHSA-92pg-8g57-hqpx
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CVSS 3.1
CWE-200
Published
Advisory Summary

CVE-2021-21621 is a LOW (CVSS 3.1) support bundles can include user vulnerability (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) affecting Support core libraries in the Maven ecosystem. The issue involves support bundles can include user session ids in jenkins support core plugin. Remediation is available by upgrading affected packages to version 2.72.1.

CVE-2021-21621 at a Glance

CVE Identifier CVE-2021-21621
GHSA Identifier GHSA-92pg-8g57-hqpx
Severity LOW
CVSS v3.1 Base Score 3.1
CWE Classification CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Affected Product Support core
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 3.1

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

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

How to Fix CVE-2021-21621

To remediate this vulnerability, upgrade all affected Support core 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.jenkins-ci.plugins:support-core fixed: 2.72.1 
<dependency>
    <groupId>org.jenkins-ci.plugins</groupId>
    <artifactId>support-core</artifactId>
    <version>2.72.1</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.jenkins-ci.plugins

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-21621, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.jenkins-ci.plugins

Analyze the terminal output to locate any version of Support core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.72.1), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.jenkins-ci.plugins 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 Support core, 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

Support Core Plugin 2.72 and earlier provides the serialized user authentication as part of the \"About user (basic authentication details only)\" information (`user.md`). In some configurations, this can include the session ID of the user creating the support bundle. Attackers with access to support bundle content and the Jenkins instance could use this information to impersonate the user who created the support bundle. Support Core Plugin 2.72.1 no longer provides the serialized user authentication as part of the \"About user (basic authentication details only)\" information. As a workaround, deselecting \"About user (basic authentication details only)\" before creating a support bundle will exclude the affected information from the bundle.

CVE-2021-21621 Affected Support core Versions

1 component(s)
Fixed Versions:
2.72.1
Product / Package Ecosystem Affected Versions Fixed Version
org.jenkins-ci.plugins:support-core
maven/org.jenkins-ci.plugins/support-core
Maven
< 2.72.1
2.72.1

References

NVD — CVE-2021-21621 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-21621
Security Fix Commit FIX COMMIT
https://github.com/jenkinsci/support-core-plugin/commit/9af9efae6e9ed408ca89ff9b5f1b7a74da0a131f
Support core Source Repository REPOSITORY
https://github.com/jenkinsci/support-core-plugin
Support core Security Information SECURITY
https://www.jenkins.io/security/advisory/2021-02-24/#SECURITY-2150

Frequently Asked Questions

What is CVE-2021-21621?
CVE-2021-21621 is a security vulnerability in Support core involving Support bundles can include user session IDs in Jenkins Support Core Plugin under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.
Which Support core versions are affected?
Affected versions include releases prior to 2.72.1 across affected packages: org.jenkins-ci.plugins:support-core.
What version fixes CVE-2021-21621?
Upgrading to 2.72.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is support-core affected?
Yes, org.jenkins-ci.plugins:support-core is affected in releases prior to 2.72.1. Upgrade your dependency to 2.72.1 or later.
What is the CVSS score of CVE-2021-21621?
CVE-2021-21621 has a CVSS v3.1 base score of 3.1 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2021-21621?
CVE-2021-21621 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-2021-21621?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.jenkins-ci.plugins'. 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 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-92pg-8g57-hqpx",
  "modified" : "2023-12-15T09:40:58Z",
  "published" : "2022-05-24T17:43:01Z",
  "aliases" : [ "CVE-2021-21621" ],
  "summary" : "Support bundles can include user session IDs in Jenkins Support Core Plugin",
  "details" : "Support Core Plugin 2.72 and earlier provides the serialized user authentication as part of the \\\"About user (basic authentication details only)\\\" information (`user.md`).\n\nIn some configurations, this can include the session ID of the user creating the support bundle. Attackers with access to support bundle content and the Jenkins instance could use this information to impersonate the user who created the support bundle.\nSupport Core Plugin 2.72.1 no longer provides the serialized user authentication as part of the \\\"About user (basic authentication details only)\\\" information.\n\nAs a workaround, deselecting \\\"About user (basic authentication details only)\\\" before creating a support bundle will exclude the affected information from the bundle.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.jenkins-ci.plugins:support-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.72.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 2.72"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-21621"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jenkinsci/support-core-plugin/commit/9af9efae6e9ed408ca89ff9b5f1b7a74da0a131f"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jenkinsci/support-core-plugin"
  }, {
    "type" : "WEB",
    "url" : "https://www.jenkins.io/security/advisory/2021-02-24/#SECURITY-2150"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-12-13T18:58:12Z",
    "nvd_published_at" : "2021-02-24T16:15:00Z"
  }
}