CVE-2021-26505: Hellojs MrSwitch Hello.js Vulnerable To Prototype Vulnerability

CRITICAL
Advisory Identifier: GHSA-g3vf-47fv-8f3c
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CVSS 9.8
CWE-1321
Published
Advisory Summary

CVE-2021-26505 is a CRITICAL (CVSS 9.8) mrswitch hello.js vulnerable to prototype vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting Hellojs libraries in the npm ecosystem. The issue involves mrswitch hello.js vulnerable to prototype pollution. Remediation is available by upgrading affected packages to version 1.18.8.

CVE-2021-26505 at a Glance

CVE Identifier CVE-2021-26505
GHSA Identifier GHSA-g3vf-47fv-8f3c
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product Hellojs
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-2021-26505

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

hellojs fixed: 1.18.8 
npm install hellojs@1.18.8
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 hellojs

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2021-26505, inspect your project dependencies using npm:

npm ls hellojs

Analyze the terminal output to locate any version of Hellojs in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.18.8), your application is affected.

Note: The npm ls hellojs 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 Hellojs, 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

A prototype pollution vulnerability in MrSwitch hello.js prior to version 1.18.8 allows remote attackers to execute arbitrary code via `hello.utils.extend` function.

CVE-2021-26505 Affected Hellojs Versions

1 component(s)
Fixed Versions:
1.18.8
Product / Package Ecosystem Affected Versions Fixed Version
hellojs
npm/hellojs
npm
< 1.18.8
1.18.8

References

NVD — CVE-2021-26505 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-26505
Hellojs Source Repository REPOSITORY
https://github.com/MrSwitch/hello.js/issues/634
Security Fix Commit FIX COMMIT
https://github.com/MrSwitch/hello.js/commit/7ab50aeff2d41991f08d4ad6c0481125eea8f6b7
Hellojs Source Repository REPOSITORY
https://github.com/MrSwitch/hello.js

Frequently Asked Questions

What is CVE-2021-26505?
CVE-2021-26505 is a security vulnerability in Hellojs involving MrSwitch hello.js vulnerable to prototype pollution under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which Hellojs versions are affected?
Affected versions include releases prior to 1.18.8 across affected packages: hellojs.
What version fixes CVE-2021-26505?
Upgrading to 1.18.8 (or the latest patched release for your respective branch) resolves the vulnerability.
Is hellojs affected?
Yes, hellojs is affected in releases prior to 1.18.8. Upgrade your dependency to 1.18.8 or later.
What is the CVSS score of CVE-2021-26505?
CVE-2021-26505 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-2021-26505?
CVE-2021-26505 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-2021-26505?
Run the dependency tree command: 'npm ls hellojs'. 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-g3vf-47fv-8f3c",
  "modified" : "2023-08-16T21:39:51Z",
  "published" : "2023-08-11T15:30:46Z",
  "aliases" : [ "CVE-2021-26505" ],
  "summary" : "MrSwitch hello.js vulnerable to prototype pollution",
  "details" : "A prototype pollution vulnerability in MrSwitch hello.js prior to version 1.18.8 allows remote attackers to execute arbitrary code via `hello.utils.extend` function.",
  "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" : "hellojs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.18.8"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-26505"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MrSwitch/hello.js/issues/634"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MrSwitch/hello.js/commit/7ab50aeff2d41991f08d4ad6c0481125eea8f6b7"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/MrSwitch/hello.js"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-08-11T22:08:41Z",
    "nvd_published_at" : "2023-08-11T14:15:12Z"
  }
}