CVE-2020-2191: Swarm Improper Permission Checks Vulnerability

MODERATE
Advisory Identifier: GHSA-j852-mp82-wv2g
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CVSS 5.4
CWE-285
Published
Advisory Summary

CVE-2020-2191 is a MODERATE (CVSS 5.4) improper permission checks vulnerability (CWE-285: Improper Authorization) affecting Swarm libraries in the Maven ecosystem. The issue involves improper permission checks in jenkins swarm plugin. Remediation is available by upgrading affected packages to version 3.21.

CVE-2020-2191 at a Glance

CVE Identifier CVE-2020-2191
GHSA Identifier GHSA-j852-mp82-wv2g
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-285: Improper Authorization
Affected Product Swarm
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.4

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:N/I:L/A:L).

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 None (C:N)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2020-2191

To remediate this vulnerability, upgrade all affected Swarm 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:swarm fixed: 3.21 
<dependency>
    <groupId>org.jenkins-ci.plugins</groupId>
    <artifactId>swarm</artifactId>
    <version>3.21</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-2020-2191, 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 Swarm in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.21), 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-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. In Swarm, 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

Swarm Plugin adds API endpoints to add or remove agent labels. In Swarm Plugin 3.20 and earlier these only require a global Swarm secret to use, and no regular permission check is performed. This allows users with Agent/Create permission to add or remove labels of any agent. Swarm Plugin 3.21 requires Agent/Configure permission for the affected agent to these endpoints. It no longer uses the global Swarm secret for these API endpoints.

CVE-2020-2191 Affected Swarm Versions

1 component(s)
Fixed Versions:
3.21
Product / Package Ecosystem Affected Versions Fixed Version
org.jenkins-ci.plugins:swarm
maven/org.jenkins-ci.plugins/swarm
Maven
< 3.21
3.21

References

NVD — CVE-2020-2191 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-2191
Security Fix Commit FIX COMMIT
https://github.com/jenkinsci/swarm-plugin/commit/4d18f98b00e4c84b152d52346fb9ef1a227b1cf7
Swarm Source Repository REPOSITORY
https://github.com/jenkinsci/swarm-plugin
Swarm Security Information SECURITY
https://jenkins.io/security/advisory/2020-06-03/#SECURITY-1200
Swarm Security Information SECURITY
http://www.openwall.com/lists/oss-security/2020/06/03/3

Frequently Asked Questions

What is CVE-2020-2191?
CVE-2020-2191 is a security vulnerability in Swarm involving Improper permission checks in Jenkins Swarm Plugin under CWE-285: Improper Authorization.
Which Swarm versions are affected?
Affected versions include releases prior to 3.21 across affected packages: org.jenkins-ci.plugins:swarm.
What version fixes CVE-2020-2191?
Upgrading to 3.21 (or the latest patched release for your respective branch) resolves the vulnerability.
Is swarm affected?
Yes, org.jenkins-ci.plugins:swarm is affected in releases prior to 3.21. Upgrade your dependency to 3.21 or later.
What is the CVSS score of CVE-2020-2191?
CVE-2020-2191 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L.
What CWE is associated with CVE-2020-2191?
CVE-2020-2191 is classified under CWE-285: Improper Authorization (The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.).
How can I check Maven dependencies for CVE-2020-2191?
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-j852-mp82-wv2g",
  "modified" : "2022-12-20T22:14:55Z",
  "published" : "2022-05-24T17:19:04Z",
  "aliases" : [ "CVE-2020-2191" ],
  "summary" : "Improper permission checks in Jenkins Swarm Plugin",
  "details" : "Swarm Plugin adds API endpoints to add or remove agent labels. In Swarm Plugin 3.20 and earlier these only require a global Swarm secret to use, and no regular permission check is performed. This allows users with Agent/Create permission to add or remove labels of any agent.\n\nSwarm Plugin 3.21 requires Agent/Configure permission for the affected agent to these endpoints. It no longer uses the global Swarm secret for these API endpoints.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.jenkins-ci.plugins:swarm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.21"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-2191"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jenkinsci/swarm-plugin/commit/4d18f98b00e4c84b152d52346fb9ef1a227b1cf7"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jenkinsci/swarm-plugin"
  }, {
    "type" : "WEB",
    "url" : "https://jenkins.io/security/advisory/2020-06-03/#SECURITY-1200"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2020/06/03/3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-285" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-12-20T22:14:55Z",
    "nvd_published_at" : "2020-06-03T13:15:00Z"
  }
}