CVE-2017-20189: Clojure Clojure Classes Can Be Used Vulnerability

CRITICAL
Advisory Identifier: GHSA-jgxc-8mwq-9xqw
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CVSS 9.8
CWE-502
Published
Advisory Summary

CVE-2017-20189 is a CRITICAL (CVSS 9.8) clojure classes can be used vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Clojure libraries in the Maven ecosystem. The issue involves clojure classes can be used to craft a serialized object that runs arbitrary code on deserialization. Remediation is available by upgrading affected packages to version 1.9.0.

CVE-2017-20189 at a Glance

CVE Identifier CVE-2017-20189
GHSA Identifier GHSA-jgxc-8mwq-9xqw
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Clojure
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.8

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:H/I:H/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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2017-20189

To remediate this vulnerability, upgrade all affected Clojure 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.clojure:clojure fixed: 1.9.0 
<dependency>
    <groupId>org.clojure</groupId>
    <artifactId>clojure</artifactId>
    <version>1.9.0</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.clojure

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2017-20189, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.clojure

Analyze the terminal output to locate any version of Clojure in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.9.0), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.clojure 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-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Clojure, 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

In Clojure before 1.9.0, classes can be used to construct a serialized object that executes arbitrary code upon deserialization. This is relevant if a server deserializes untrusted objects.

CVE-2017-20189 Affected Clojure Versions

1 component(s)
Fixed Versions:
1.9.0
Product / Package Ecosystem Affected Versions Fixed Version
org.clojure:clojure
maven/org.clojure/clojure
Maven
< 1.9.0
1.9.0

References

NVD — CVE-2017-20189 NVD
https://nvd.nist.gov/vuln/detail/CVE-2017-20189
Clojure Source Repository REPOSITORY
https://github.com/frohoff/ysoserial/pull/68/files
Security Fix Commit FIX COMMIT
https://github.com/clojure/clojure/commit/271674c9b484d798484d134a5ac40a6df15d3ac3
Clojure Security Information SECURITY
https://clojure.atlassian.net/browse/CLJ-2204
Clojure Source Repository REPOSITORY
https://github.com/clojure/clojure
groups.google.com/d/msg/clojure/wal3h... WEB
https://groups.google.com/d/msg/clojure/WaL3hHzsevI/7zHU-L7LBQAJ
hackmd.io/@fe1w0/hyefvrqkp WEB
https://hackmd.io/%40fe1w0/HyefvRQKp
Clojure Security Information SECURITY
https://security.netapp.com/advisory/ntap-20241108-0002
Clojure Security Information SECURITY
https://security.snyk.io/vuln/SNYK-JAVA-ORGCLOJURE-5740378

Frequently Asked Questions

What is CVE-2017-20189?
CVE-2017-20189 is a security vulnerability in Clojure involving Clojure classes can be used to craft a serialized object that runs arbitrary code on deserialization under CWE-502: Deserialization of Untrusted Data.
Which Clojure versions are affected?
Affected versions include releases prior to 1.9.0 across affected packages: org.clojure:clojure.
What version fixes CVE-2017-20189?
Upgrading to 1.9.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is clojure affected?
Yes, org.clojure:clojure is affected in releases prior to 1.9.0. Upgrade your dependency to 1.9.0 or later.
What is the CVSS score of CVE-2017-20189?
CVE-2017-20189 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2017-20189?
CVE-2017-20189 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check Maven dependencies for CVE-2017-20189?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.clojure'. 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-jgxc-8mwq-9xqw",
  "modified" : "2025-11-04T00:30:44Z",
  "published" : "2024-01-22T06:30:32Z",
  "aliases" : [ "CVE-2017-20189" ],
  "summary" : "Clojure classes can be used to craft a serialized object that runs arbitrary code on deserialization",
  "details" : "In Clojure before 1.9.0, classes can be used to construct a serialized object that executes arbitrary code upon deserialization. This is relevant if a server deserializes untrusted objects.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.clojure:clojure"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.9.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2017-20189"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/frohoff/ysoserial/pull/68/files"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/clojure/clojure/commit/271674c9b484d798484d134a5ac40a6df15d3ac3"
  }, {
    "type" : "WEB",
    "url" : "https://clojure.atlassian.net/browse/CLJ-2204"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/clojure/clojure"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/d/msg/clojure/WaL3hHzsevI/7zHU-L7LBQAJ"
  }, {
    "type" : "WEB",
    "url" : "https://hackmd.io/%40fe1w0/HyefvRQKp"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20241108-0002"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-JAVA-ORGCLOJURE-5740378"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-01-22T21:25:51Z",
    "nvd_published_at" : "2024-01-22T06:15:07Z"
  }
}