CVE-2021-25953: Putil merge Prototype Pollution Vulnerability

CRITICAL
Advisory Identifier: GHSA-9x7m-9hpg-xxmw
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CVSS 9.8
CWE-1321
Published
Advisory Summary

CVE-2021-25953 is a CRITICAL (CVSS 9.8) prototype pollution vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting Putil merge libraries in the npm ecosystem. The issue involves prototype pollution in putil-merge. Remediation is available by upgrading affected packages to version 3.7.0.

CVE-2021-25953 at a Glance

CVE Identifier CVE-2021-25953
GHSA Identifier GHSA-9x7m-9hpg-xxmw
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product Putil merge
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-2021-25953

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

putil-merge fixed: 3.7.0 
npm install putil-merge@3.7.0
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 putil-merge

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2021-25953, inspect your project dependencies using npm:

npm ls putil-merge

Analyze the terminal output to locate any version of Putil merge in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.7.0), your application is affected.

Note: The npm ls putil-merge 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 Putil merge, 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 'putil-merge' versions1.0.0 through 3.6.6 allows attacker to cause a denial of service and may lead to remote code execution.

CVE-2021-25953 Affected Putil merge Versions

1 component(s)
Fixed Versions:
3.7.0
Product / Package Ecosystem Affected Versions Fixed Version
putil-merge
npm/putil-merge
npm
≥ 1.0.0
< 3.7.0
3.7.0

References

NVD — CVE-2021-25953 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-25953
www.whitesourcesoftware.com/vulnerability-datab... WEB
https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25953

Frequently Asked Questions

What is CVE-2021-25953?
CVE-2021-25953 is a security vulnerability in Putil merge involving Prototype Pollution in putil-merge under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which Putil merge versions are affected?
Affected versions include releases prior to 3.7.0 across affected packages: putil-merge.
What version fixes CVE-2021-25953?
Upgrading to 3.7.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is putil-merge affected?
Yes, putil-merge is affected in releases prior to 3.7.0. Upgrade your dependency to 3.7.0 or later.
What is the CVSS score of CVE-2021-25953?
CVE-2021-25953 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-2021-25953?
CVE-2021-25953 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-2021-25953?
Run the dependency tree command: 'npm ls putil-merge'. 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-9x7m-9hpg-xxmw",
  "modified" : "2021-07-19T15:44:57Z",
  "published" : "2021-12-10T17:24:16Z",
  "aliases" : [ "CVE-2021-25953" ],
  "summary" : "Prototype Pollution in putil-merge",
  "details" : "Prototype pollution vulnerability in 'putil-merge' versions1.0.0 through 3.6.6 allows 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" : "putil-merge"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.0.0"
      }, {
        "fixed" : "3.7.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.6.6"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-25953"
  }, {
    "type" : "WEB",
    "url" : "https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25953"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-07-15T20:19:36Z",
    "nvd_published_at" : "2021-07-14T11:15:00Z"
  }
}