CVE-2021-32821: Mootools Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-v63q-hgqc-qvpg
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CVSS 7.5
CWE-400 CWE-1333
Published
Advisory Summary

CVE-2021-32821 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Mootools libraries in the npm ecosystem. The issue involves mootools regular expression denial of service. Remediation is available in the latest vendor maintenance releases.

CVE-2021-32821 at a Glance

CVE Identifier CVE-2021-32821
GHSA Identifier GHSA-v63q-hgqc-qvpg
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Mootools
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.5

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:N/I:N/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 None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2021-32821

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

mootools fixed: Latest secure release 
npm install mootools@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 mootools

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2021-32821, inspect your project dependencies using npm:

npm ls mootools

Analyze the terminal output to locate any version of Mootools 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 mootools 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-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Mootools, 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

MooTools is a collection of JavaScript utilities for JavaScript developers. All known versions include a CSS selector parser that is vulnerable to Regular Expression Denial of Service (ReDoS). An attack requires that an attacker can inject a string into a CSS selector at runtime, which is quite common with e.g. jQuery CSS selectors. No patches are available for this issue.

CVE-2021-32821 Affected Mootools Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
mootools
npm/mootools
npm
≤ 1.5.2

References

NVD — CVE-2021-32821 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-32821
Mootools Source Repository REPOSITORY
https://github.com/vsviridov/mootools-node
GitHub Advisory / Wiki ADVISORY
https://securitylab.github.com/advisories/GHSL-2020-345-redos-mootools

Frequently Asked Questions

What is CVE-2021-32821?
CVE-2021-32821 is a security vulnerability in Mootools involving MooTools Regular Expression Denial of Service under CWE-400: Uncontrolled Resource Consumption.
Which Mootools versions are affected?
Affected versions include releases prior to current release patches across affected packages: mootools.
What version fixes CVE-2021-32821?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is mootools affected?
Yes, mootools 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-2021-32821?
CVE-2021-32821 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2021-32821?
CVE-2021-32821 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check npm dependencies for CVE-2021-32821?
Run the dependency tree command: 'npm ls mootools'. 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-v63q-hgqc-qvpg",
  "modified" : "2024-04-02T14:07:06Z",
  "published" : "2023-01-03T18:30:25Z",
  "aliases" : [ "CVE-2021-32821" ],
  "summary" : "MooTools Regular Expression Denial of Service",
  "details" : "MooTools is a collection of JavaScript utilities for JavaScript developers. All known versions include a CSS selector parser that is vulnerable to Regular Expression Denial of Service (ReDoS). An attack requires that an attacker can inject a string into a CSS selector at runtime, which is quite common with e.g. jQuery CSS selectors. No patches are available for this issue.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "mootools"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.5.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-32821"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/vsviridov/mootools-node"
  }, {
    "type" : "ADVISORY",
    "url" : "https://securitylab.github.com/advisories/GHSL-2020-345-redos-mootools"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1333", "CWE-400" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-04-02T14:06:51Z",
    "nvd_published_at" : "2023-01-03T17:15:00Z"
  }
}