CVE-2021-23558: Bmoor Prototype Pollution Vulnerability

HIGH
Advisory Identifier: GHSA-4m8h-h59m-m34j
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CVSS 7.3
CWE-1321
Published
Advisory Summary

CVE-2021-23558 is a HIGH (CVSS 7.3) prototype pollution vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting Bmoor libraries in the npm ecosystem. The issue involves prototype pollution in bmoor. Remediation is available by upgrading affected packages to version 0.10.1.

CVE-2021-23558 at a Glance

CVE Identifier CVE-2021-23558
GHSA Identifier GHSA-4m8h-h59m-m34j
Severity HIGH
CVSS v3.1 Base Score 7.3
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product Bmoor
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.3

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:L/I:L/A:L).

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 Low (C:L)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2021-23558

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

bmoor fixed: 0.10.1 
npm install bmoor@0.10.1
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 bmoor

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2021-23558, inspect your project dependencies using npm:

npm ls bmoor

Analyze the terminal output to locate any version of Bmoor in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.10.1), your application is affected.

Note: The npm ls bmoor 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 Bmoor, 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

The package bmoor before 0.10.1 is vulnerable to Prototype Pollution due to missing sanitization in set function. **Note:** This vulnerability derives from an incomplete fix in [CVE-2020-7736](https://security.snyk.io/vuln/SNYK-JS-BMOOR-598664)

CVE-2021-23558 Affected Bmoor Versions

1 component(s)
Fixed Versions:
0.10.1
Product / Package Ecosystem Affected Versions Fixed Version
bmoor
npm/bmoor
npm
< 0.10.1
0.10.1

References

NVD — CVE-2021-23558 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-23558
Security Fix Commit FIX COMMIT
https://github.com/b-heilman/bmoor/commit/29b0162cc1dc1791fc060891f568b0ae29bc542b
Bmoor Source Repository REPOSITORY
https://github.com/b-heilman/bmoor
Bmoor Security Information SECURITY
https://security.snyk.io/vuln/SNYK-JS-BMOOR-598664
snyk.io/blog/remediate-java... WEB
https://snyk.io/blog/remediate-javascript-type-confusion-bypassed-input-validation
snyk.io/vuln/snyk-js-bmoor-... WEB
https://snyk.io/vuln/SNYK-JS-BMOOR-2342622

Frequently Asked Questions

What is CVE-2021-23558?
CVE-2021-23558 is a security vulnerability in Bmoor involving Prototype Pollution in bmoor under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which Bmoor versions are affected?
Affected versions include releases prior to 0.10.1 across affected packages: bmoor.
What version fixes CVE-2021-23558?
Upgrading to 0.10.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is bmoor affected?
Yes, bmoor is affected in releases prior to 0.10.1. Upgrade your dependency to 0.10.1 or later.
What is the CVSS score of CVE-2021-23558?
CVE-2021-23558 has a CVSS v3.1 base score of 7.3 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
What CWE is associated with CVE-2021-23558?
CVE-2021-23558 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-2021-23558?
Run the dependency tree command: 'npm ls bmoor'. 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-4m8h-h59m-m34j",
  "modified" : "2022-02-07T21:21:00Z",
  "published" : "2022-02-01T00:50:09Z",
  "aliases" : [ "CVE-2021-23558" ],
  "summary" : "Prototype Pollution in bmoor",
  "details" : "The package bmoor before 0.10.1 is vulnerable to Prototype Pollution due to missing sanitization in set function. **Note:** This vulnerability derives from an incomplete fix in [CVE-2020-7736](https://security.snyk.io/vuln/SNYK-JS-BMOOR-598664)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "bmoor"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.10.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-23558"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/b-heilman/bmoor/commit/29b0162cc1dc1791fc060891f568b0ae29bc542b"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/b-heilman/bmoor"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-JS-BMOOR-598664"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/blog/remediate-javascript-type-confusion-bypassed-input-validation"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-JS-BMOOR-2342622"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-01-31T20:51:31Z",
    "nvd_published_at" : "2022-01-28T22:15:00Z"
  }
}