Vulnerabilities in pkg:npm/markdown-it-toc

PACKAGE
Advisory Identifier: GHSA-wfvx-fx73-3rfj
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Advisory Summary

CVE-2020-28455 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 it toc libraries in the npm ecosystem. The issue involves markdown-it-toc cross-site scripting due to title of generated toc and contents of header not being escaped. Remediation is available in the latest vendor maintenance releases.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:npm/markdown-it-toc

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:npm/markdown-it-toc. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-wfvx-fx73-3rfj CVE-2020-28455 MODERATE markdown-it-toc Cross-site Scripting due to title of generated toc and contents of header not being escaped

CVE-2020-28455 at a Glance

CVE Identifier CVE-2020-28455
GHSA Identifier GHSA-wfvx-fx73-3rfj
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 it toc
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-2020-28455

To remediate this vulnerability, upgrade all affected Markdown it toc 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-it-toc fixed: Latest secure release 
npm install markdown-it-toc@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 markdown-it-toc

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2020-28455, inspect your project dependencies using npm:

npm ls markdown-it-toc

Analyze the terminal output to locate any version of Markdown it toc 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 markdown-it-toc 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 it toc, 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

This affects all versions of package markdown-it-toc. The title of the generated toc and the contents of the header are not escaped.

CVE-2020-28455 Affected Markdown it toc Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
markdown-it-toc
npm/markdown-it-toc
npm
≤ 1.1.0

References

NVD — CVE-2020-28455 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-28455
Markdown it toc Security Information SECURITY
https://security.snyk.io/vuln/SNYK-JS-MARKDOWNITTOC-1044067

Frequently Asked Questions

What is CVE-2020-28455?
CVE-2020-28455 is a security vulnerability in Markdown it toc involving markdown-it-toc Cross-site Scripting due to title of generated toc and contents of header not being escaped under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Markdown it toc versions are affected?
Affected versions include releases prior to current release patches across affected packages: markdown-it-toc.
What version fixes CVE-2020-28455?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is markdown-it-toc affected?
Yes, markdown-it-toc 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-2020-28455?
CVE-2020-28455 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-2020-28455?
CVE-2020-28455 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-2020-28455?
Run the dependency tree command: 'npm ls markdown-it-toc'. 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-wfvx-fx73-3rfj",
  "modified" : "2022-08-06T09:35:55Z",
  "published" : "2022-07-26T00:01:05Z",
  "aliases" : [ "CVE-2020-28455" ],
  "summary" : "markdown-it-toc Cross-site Scripting due to title of generated toc and contents of header not being escaped",
  "details" : "This affects all versions of package markdown-it-toc. The title of the generated toc and the contents of the header are not escaped.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "markdown-it-toc"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.1.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-28455"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-JS-MARKDOWNITTOC-1044067"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-08-06T09:35:55Z",
    "nvd_published_at" : "2022-07-25T14:15:00Z"
  }
}