CVE-2024-21535: Markdown to jsx Cross Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-4wx3-54gh-9fr9
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CVSS 6.1
CWE-79
Published
Advisory Summary

CVE-2024-21535 is a MODERATE (CVSS 6.1) cross site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Markdown to jsx libraries in the npm ecosystem. The issue involves cross site scripting in markdown-to-jsx. Remediation is available by upgrading affected packages to version 7.4.0.

CVE-2024-21535 at a Glance

CVE Identifier CVE-2024-21535
GHSA Identifier GHSA-4wx3-54gh-9fr9
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Markdown to jsx
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 6.1

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:R/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2024-21535

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

markdown-to-jsx fixed: 7.4.0 
npm install markdown-to-jsx@7.4.0
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 markdown-to-jsx

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2024-21535, inspect your project dependencies using npm:

npm ls markdown-to-jsx

Analyze the terminal output to locate any version of Markdown to jsx in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.4.0), your application is affected.

Note: The npm ls markdown-to-jsx 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-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Markdown to jsx, 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

Versions of the package markdown-to-jsx before 7.4.0 are vulnerable to Cross-site Scripting (XSS) via the src property due to improper input sanitization. An attacker can execute arbitrary code by injecting a malicious iframe element in the markdown.

CVE-2024-21535 Affected Markdown to jsx Versions

1 component(s)
Fixed Versions:
7.4.0
Product / Package Ecosystem Affected Versions Fixed Version
markdown-to-jsx
npm/markdown-to-jsx
npm
< 7.4.0
7.4.0

References

Markdown to jsx Security Information SECURITY
https://security.snyk.io/vuln/SNYK-JS-MARKDOWNTOJSX-6258886
NVD — CVE-2024-21535 NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-21535
Security Fix Commit FIX COMMIT
https://github.com/quantizor/markdown-to-jsx/commit/8eb74da825c0d8d2e9508d73c672bcae36ba555a
Markdown to jsx Source Repository REPOSITORY
https://github.com/quantizor/markdown-to-jsx

Frequently Asked Questions

What is CVE-2024-21535?
CVE-2024-21535 is a security vulnerability in Markdown to jsx involving Cross site scripting in markdown-to-jsx under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Markdown to jsx versions are affected?
Affected versions include releases prior to 7.4.0 across affected packages: markdown-to-jsx.
What version fixes CVE-2024-21535?
Upgrading to 7.4.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is markdown-to-jsx affected?
Yes, markdown-to-jsx is affected in releases prior to 7.4.0. Upgrade your dependency to 7.4.0 or later.
What is the CVSS score of CVE-2024-21535?
CVE-2024-21535 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2024-21535?
CVE-2024-21535 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check npm dependencies for CVE-2024-21535?
Run the dependency tree command: 'npm ls markdown-to-jsx'. 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-4wx3-54gh-9fr9",
  "modified" : "2024-10-15T17:36:26Z",
  "published" : "2024-10-15T06:30:31Z",
  "aliases" : [ "CVE-2024-21535" ],
  "summary" : "Cross site scripting in markdown-to-jsx",
  "details" : "Versions of the package markdown-to-jsx before 7.4.0 are vulnerable to Cross-site Scripting (XSS) via the src property due to improper input sanitization. An attacker can execute arbitrary code by injecting a malicious iframe element in the markdown.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "markdown-to-jsx"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "7.4.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-21535"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/quantizor/markdown-to-jsx/commit/8eb74da825c0d8d2e9508d73c672bcae36ba555a"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/quantizor/markdown-to-jsx"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-JS-MARKDOWNTOJSX-6258886"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-10-15T17:36:26Z",
    "nvd_published_at" : "2024-10-15T05:15:11Z"
  }
}