CVE-2021-23448: Config handler Prototype Pollution Vulnerability

CRITICAL
Advisory Identifier: GHSA-2w3f-9w3q-qw77
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CVSS 9.8
CWE-913
Published
Advisory Summary

CVE-2021-23448 is a CRITICAL (CVSS 9.8) prototype pollution vulnerability (CWE-913: Improper Control of Dynamically-Managed Code Resources) affecting Config handler libraries in the npm ecosystem. The issue involves prototype pollution in config-handler. Remediation is available in the latest vendor maintenance releases.

CVE-2021-23448 at a Glance

CVE Identifier CVE-2021-23448
GHSA Identifier GHSA-2w3f-9w3q-qw77
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-913: Improper Control of Dynamically-Managed Code Resources
Affected Product Config handler
Package Ecosystem npm
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-2021-23448

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

config-handler fixed: Latest secure release 
npm install config-handler@Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls config-handler

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2021-23448, inspect your project dependencies using npm:

npm ls config-handler

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

Note: The npm ls config-handler command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-913: Improper Control of Dynamically-Managed Code Resources, where the product does not properly restrict reading from or writing to dynamically-managed code resources such as variables, objects, classes, attributes, functions, or executable instructions or statements. In Config handler, 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

All versions of package config-handler are vulnerable to Prototype Pollution when loading config files.

CVE-2021-23448 Affected Config handler Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
config-handler
npm/config-handler
npm
≤ 2.0.3

References

NVD — CVE-2021-23448 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-23448
Config handler Source Repository REPOSITORY
https://github.com/jarradseers/config-handler/issues/1
Config handler Source Repository REPOSITORY
https://github.com/jarradseers/config-handler
snyk.io/vuln/snyk-js-config... WEB
https://snyk.io/vuln/SNYK-JS-CONFIGHANDLER-1564947

Frequently Asked Questions

What is CVE-2021-23448?
CVE-2021-23448 is a security vulnerability in Config handler involving Prototype Pollution in config-handler under CWE-913: Improper Control of Dynamically-Managed Code Resources.
Which Config handler versions are affected?
Affected versions include releases prior to current release patches across affected packages: config-handler.
What version fixes CVE-2021-23448?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is config-handler affected?
Yes, config-handler is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2021-23448?
CVE-2021-23448 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-2021-23448?
CVE-2021-23448 is classified under CWE-913: Improper Control of Dynamically-Managed Code Resources (The product does not properly restrict reading from or writing to dynamically-managed code resources such as variables, objects, classes, attributes, functions, or executable instructions or statements.).
How can I check npm dependencies for CVE-2021-23448?
Run the dependency tree command: 'npm ls config-handler'. 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-2w3f-9w3q-qw77",
  "modified" : "2021-10-20T17:12:24Z",
  "published" : "2021-10-12T18:30:37Z",
  "aliases" : [ "CVE-2021-23448" ],
  "summary" : "Prototype Pollution in config-handler",
  "details" : "All versions of package config-handler are vulnerable to Prototype Pollution when loading config files.",
  "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" : "npm",
      "name" : "config-handler"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.0.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-23448"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jarradseers/config-handler/issues/1"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jarradseers/config-handler"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-JS-CONFIGHANDLER-1564947"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-913" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-10-12T17:01:08Z",
    "nvd_published_at" : "2021-10-11T21:15:00Z"
  }
}