CVE-2021-25946: Nconf toml Prototype Pollution Vulnerability

CRITICAL
Advisory Identifier: GHSA-hx7j-43w2-7rj7
Share
CVSS 9.8
CWE-1321
Published
Advisory Summary

CVE-2021-25946 is a CRITICAL (CVSS 9.8) prototype pollution vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting Nconf toml libraries in the npm ecosystem. The issue involves prototype pollution in nconf-toml. Remediation is available in the latest vendor maintenance releases.

CVE-2021-25946 at a Glance

CVE Identifier CVE-2021-25946
GHSA Identifier GHSA-hx7j-43w2-7rj7
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product Nconf toml
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-2021-25946

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

nconf-toml fixed: Latest secure release 
npm install nconf-toml@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 nconf-toml

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2021-25946, inspect your project dependencies using npm:

npm ls nconf-toml

Analyze the terminal output to locate any version of Nconf toml 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 nconf-toml 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-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'), where the product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. In Nconf toml, 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

Prototype pollution vulnerability in `nconf-toml` versions 0.0.1 through 0.0.2 allows an attacker to cause a denial of service and may lead to remote code execution.

CVE-2021-25946 Affected Nconf toml Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
nconf-toml
npm/nconf-toml
npm
≥ 0.0.1
≤ 0.0.2

References

NVD — CVE-2021-25946 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-25946
Nconf toml Source Repository REPOSITORY
https://github.com/RobLoach/nconf-toml
Nconf toml Source Repository REPOSITORY
https://github.com/RobLoach/nconf-toml/blob/8ade08cd1cfb9691ab7cc5c3514cc05c5085918f/index.js#L8
www.whitesourcesoftware.com/vulnerability-datab... WEB
https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25946

Frequently Asked Questions

What is CVE-2021-25946?
CVE-2021-25946 is a security vulnerability in Nconf toml involving Prototype pollution in nconf-toml under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which Nconf toml versions are affected?
Affected versions include releases prior to current release patches across affected packages: nconf-toml.
What version fixes CVE-2021-25946?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is nconf-toml affected?
Yes, nconf-toml 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-2021-25946?
CVE-2021-25946 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-2021-25946?
CVE-2021-25946 is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.).
How can I check npm dependencies for CVE-2021-25946?
Run the dependency tree command: 'npm ls nconf-toml'. 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-hx7j-43w2-7rj7",
  "modified" : "2021-10-05T17:22:38Z",
  "published" : "2021-06-07T22:12:13Z",
  "aliases" : [ "CVE-2021-25946" ],
  "summary" : "Prototype pollution in nconf-toml",
  "details" : "Prototype pollution vulnerability in `nconf-toml` versions 0.0.1 through 0.0.2 allows an attacker to cause a denial of service and may lead to remote code execution.",
  "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" : "nconf-toml"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.0.1"
      }, {
        "last_affected" : "0.0.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-25946"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/RobLoach/nconf-toml"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/RobLoach/nconf-toml/blob/8ade08cd1cfb9691ab7cc5c3514cc05c5085918f/index.js#L8"
  }, {
    "type" : "WEB",
    "url" : "https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25946"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-05-28T21:58:39Z",
    "nvd_published_at" : "2021-05-25T19:15:00Z"
  }
}