CVE-2022-0748: Post loader Arbitrary Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-66ww-999q-mffq
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CVSS 9.8
CWE-79
Published
Advisory Summary

CVE-2022-0748 is a CRITICAL (CVSS 9.8) arbitrary code execution vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Post loader libraries in the npm ecosystem. The issue involves arbitrary code execution in post-loader. Remediation is available in the latest vendor maintenance releases.

CVE-2022-0748 at a Glance

CVE Identifier CVE-2022-0748
GHSA Identifier GHSA-66ww-999q-mffq
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Post loader
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 9.8

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:H/I:H/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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2022-0748

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

post-loader fixed: Latest secure release 
npm install post-loader@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 post-loader

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2022-0748, inspect your project dependencies using npm:

npm ls post-loader

Analyze the terminal output to locate any version of Post loader 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 post-loader 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 Post loader, 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

post-loader is webpack loader for blog posts written in Markdown. The package post-loader from 0.0.0 is vulnerable to Arbitrary Code Execution which uses a markdown parser in an unsafe way so that any javascript code inside the markdown input files gets evaluated and executed. At this time, there is no known workaround or patch available.

CVE-2022-0748 Affected Post loader Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
post-loader
npm/post-loader
npm
≥ 0.0.0

References

NVD — CVE-2022-0748 NVD
https://nvd.nist.gov/vuln/detail/CVE-2022-0748
Post loader Source Repository REPOSITORY
https://github.com/egoist/post-loader
snyk.io/vuln/snyk-js-postlo... WEB
https://snyk.io/vuln/SNYK-JS-POSTLOADER-2403737

Frequently Asked Questions

What is CVE-2022-0748?
CVE-2022-0748 is a security vulnerability in Post loader involving Arbitrary code execution in post-loader under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Post loader versions are affected?
Affected versions include releases prior to current release patches across affected packages: post-loader.
What version fixes CVE-2022-0748?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is post-loader affected?
Yes, post-loader 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-2022-0748?
CVE-2022-0748 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2022-0748?
CVE-2022-0748 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-2022-0748?
Run the dependency tree command: 'npm ls post-loader'. 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-66ww-999q-mffq",
  "modified" : "2022-03-25T14:29:33Z",
  "published" : "2022-03-18T00:01:11Z",
  "aliases" : [ "CVE-2022-0748" ],
  "summary" : "Arbitrary code execution in post-loader",
  "details" : "post-loader is webpack loader for blog posts written in Markdown. The package post-loader from 0.0.0 is vulnerable to Arbitrary Code Execution which uses a markdown parser in an unsafe way so that any javascript code inside the markdown input files gets evaluated and executed. At this time, there is no known workaround or patch available.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "post-loader"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2022-0748"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/egoist/post-loader"
  }, {
    "type" : "WEB",
    "url" : "https://snyk.io/vuln/SNYK-JS-POSTLOADER-2403737"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-03-18T23:01:29Z",
    "nvd_published_at" : "2022-03-17T12:15:00Z"
  }
}