CVE-2019-10905: Erusev/parsedown Parsedown Class-Name Injection Vulnerability

HIGH
Advisory Identifier: GHSA-62m3-fc7f-jpp8
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CVSS 8.1
CWE-79
Published
Advisory Summary

CVE-2019-10905 is a HIGH (CVSS 8.1) parsedown class-name injection vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Erusev/parsedown libraries in the Packagist ecosystem. The issue involves parsedown class-name injection. Remediation is available by upgrading affected packages to version 1.7.2.

CVE-2019-10905 at a Glance

CVE Identifier CVE-2019-10905
GHSA Identifier GHSA-62m3-fc7f-jpp8
Severity HIGH
CVSS v3.1 Base Score 8.1
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Erusev/parsedown
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
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-2019-10905

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

erusev/parsedown fixed: 1.7.2 
Upgrade erusev/parsedown to 1.7.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for erusev/parsedown

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-10905, inspect your project dependencies for Erusev/parsedown:

inspect dependencies for erusev/parsedown

Analyze the terminal output to locate any version of Erusev/parsedown in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.7.2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

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 Erusev/parsedown, 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

Parsedown before 1.7.2, when safe mode is used and HTML markup is disabled, might allow attackers to execute arbitrary JavaScript code if a script (already running on the affected page) executes the contents of any element with a specific class. This occurs because spaces are permitted in code block infostrings, which interferes with the intended behavior of a single class name beginning with the language- substring.

CVE-2019-10905 Affected Erusev/parsedown Versions

1 component(s)
Fixed Versions:
1.7.2
Product / Package Ecosystem Affected Versions Fixed Version
erusev/parsedown
 Packagist
< 1.7.2
1.7.2

References

NVD — CVE-2019-10905 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-10905
Erusev/parsedown Source Repository REPOSITORY
https://github.com/erusev/parsedown/issues/699
Erusev/parsedown Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/erusev/parsedown/CVE-2019-10905.yaml
Erusev/parsedown Source Repository REPOSITORY
https://github.com/erusev/parsedown
Erusev/parsedown Release RELEASE
https://github.com/erusev/parsedown/releases/tag/1.7.2

Frequently Asked Questions

What is CVE-2019-10905?
CVE-2019-10905 is a security vulnerability in Erusev/parsedown involving Parsedown Class-Name Injection under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Erusev/parsedown versions are affected?
Affected versions include releases prior to 1.7.2 across affected packages: erusev/parsedown.
What version fixes CVE-2019-10905?
Upgrading to 1.7.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is erusev/parsedown affected?
Yes, erusev/parsedown is affected in releases prior to 1.7.2. Upgrade your dependency to 1.7.2 or later.
What is the CVSS score of CVE-2019-10905?
CVE-2019-10905 has a CVSS v3.1 base score of 8.1 (HIGH) with vector string CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2019-10905?
CVE-2019-10905 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 Packagist dependencies for CVE-2019-10905?
Run the dependency tree command: 'inspect dependencies for erusev/parsedown'. 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-62m3-fc7f-jpp8",
  "modified" : "2023-09-11T15:01:47Z",
  "published" : "2022-03-26T00:09:58Z",
  "aliases" : [ "CVE-2019-10905" ],
  "summary" : "Parsedown Class-Name Injection",
  "details" : "Parsedown before 1.7.2, when safe mode is used and HTML markup is disabled, might allow attackers to execute arbitrary JavaScript code if a script (already running on the affected page) executes the contents of any element with a specific class. This occurs because spaces are permitted in code block infostrings, which interferes with the intended behavior of a single class name beginning with the language- substring.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "erusev/parsedown"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.7.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-10905"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/erusev/parsedown/issues/699"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/erusev/parsedown/CVE-2019-10905.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/erusev/parsedown"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/erusev/parsedown/releases/tag/1.7.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-03-26T00:09:58Z",
    "nvd_published_at" : null
  }
}