CVE-2021-25738: Client java Code Injection Vulnerability

MODERATE
Advisory Identifier: GHSA-m8wh-mqgf-rr8g
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CVSS 6.7
CWE-502 CWE-20
Published
Advisory Summary

CVE-2021-25738 is a MODERATE (CVSS 6.7) code injection vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Client java libraries in the Maven ecosystem. The issue involves code injection in kubernetes java client. Remediation is available by upgrading affected packages to version 11.0.1.

CVE-2021-25738 at a Glance

CVE Identifier CVE-2021-25738
GHSA Identifier GHSA-m8wh-mqgf-rr8g
Severity MODERATE
CVSS v3.1 Base Score 6.7
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Client java
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.7

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

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
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-2021-25738

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

io.kubernetes:client-java fixed: 11.0.1 
<dependency>
    <groupId>io.kubernetes</groupId>
    <artifactId>client-java</artifactId>
    <version>11.0.1</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=io.kubernetes

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-25738, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=io.kubernetes

Analyze the terminal output to locate any version of Client java in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 11.0.1), your application is affected.

Note: The mvn dependency:tree -Dincludes=io.kubernetes 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 Client java, 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

Loading specially-crafted yaml with the Kubernetes Java Client library can lead to code execution.

CVE-2021-25738 Affected Client java Versions

1 component(s)
Fixed Versions:
11.0.1
Product / Package Ecosystem Affected Versions Fixed Version
io.kubernetes:client-java
maven/io.kubernetes/client-java
Maven
< 11.0.1
11.0.1

References

Client java Source Repository REPOSITORY
https://github.com/kubernetes-client/java
NVD — CVE-2021-25738 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-25738
Client java Source Repository REPOSITORY
https://github.com/kubernetes-client/java/issues/1698
Client java Security Information SECURITY
https://groups.google.com/g/kubernetes-security-announce/c/K_pOK2WbAJk
Client java Security Information SECURITY
http://www.openwall.com/lists/oss-security/2022/08/23/2

Frequently Asked Questions

What is CVE-2021-25738?
CVE-2021-25738 is a security vulnerability in Client java involving Code injection in Kubernetes Java Client under CWE-502: Deserialization of Untrusted Data.
Which Client java versions are affected?
Affected versions include releases prior to 11.0.1 across affected packages: io.kubernetes:client-java.
What version fixes CVE-2021-25738?
Upgrading to 11.0.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is client-java affected?
Yes, io.kubernetes:client-java is affected in releases prior to 11.0.1. Upgrade your dependency to 11.0.1 or later.
What is the CVSS score of CVE-2021-25738?
CVE-2021-25738 has a CVSS v3.1 base score of 6.7 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-25738?
CVE-2021-25738 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-2021-25738?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=io.kubernetes'. 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-m8wh-mqgf-rr8g",
  "modified" : "2021-10-12T16:59:26Z",
  "published" : "2021-10-12T17:50:25Z",
  "aliases" : [ "CVE-2021-25738" ],
  "summary" : "Code injection in Kubernetes Java Client",
  "details" : "Loading specially-crafted yaml with the Kubernetes Java Client library can lead to code execution.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "io.kubernetes:client-java"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "11.0.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-25738"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kubernetes-client/java/issues/1698"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kubernetes-client/java"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/g/kubernetes-security-announce/c/K_pOK2WbAJk"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2022/08/23/2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20", "CWE-502" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-10-12T16:59:26Z",
    "nvd_published_at" : "2021-10-11T19:15:00Z"
  }
}