CVE-2020-28847: Valine Cross Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-6xvq-2gj8-4276
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CVSS 5.4
CWE-79
Published
Advisory Summary

CVE-2020-28847 is a MODERATE (CVSS 5.4) cross site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Valine libraries in the npm ecosystem. The issue involves cross site scripting in valine. Remediation is available by upgrading affected packages to version 1.4.15.

CVE-2020-28847 at a Glance

CVE Identifier CVE-2020-28847
GHSA Identifier GHSA-6xvq-2gj8-4276
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Valine
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
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-2020-28847

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

valine fixed: 1.4.15 
npm install valine@1.4.15
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 valine

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2020-28847, inspect your project dependencies using npm:

npm ls valine

Analyze the terminal output to locate any version of Valine in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.4.15), your application is affected.

Note: The npm ls valine 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 Valine, 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

valine is a fast, simple & powerful comment system. Cross Site Scripting (XSS) vulnerability in xCss Valine v1.4.14 via the nick parameter to /classes/Comment. A fix was released in version 1.4.15.

CVE-2020-28847 Affected Valine Versions

1 component(s)
Fixed Versions:
1.4.15
Product / Package Ecosystem Affected Versions Fixed Version
valine
npm/valine
npm
< 1.4.15
1.4.15

References

NVD — CVE-2020-28847 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-28847
Valine Source Repository REPOSITORY
https://github.com/xCss/Valine/issues/348
Valine Source Repository REPOSITORY
https://github.com/xCss/Valine
Valine Release RELEASE
https://github.com/xCss/Valine/releases/tag/v1.4.15

Frequently Asked Questions

What is CVE-2020-28847?
CVE-2020-28847 is a security vulnerability in Valine involving Cross site scripting in valine under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Valine versions are affected?
Affected versions include releases prior to 1.4.15 across affected packages: valine.
What version fixes CVE-2020-28847?
Upgrading to 1.4.15 (or the latest patched release for your respective branch) resolves the vulnerability.
Is valine affected?
Yes, valine is affected in releases prior to 1.4.15. Upgrade your dependency to 1.4.15 or later.
What is the CVSS score of CVE-2020-28847?
CVE-2020-28847 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2020-28847?
CVE-2020-28847 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-2020-28847?
Run the dependency tree command: 'npm ls valine'. 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-6xvq-2gj8-4276",
  "modified" : "2022-04-15T03:05:55Z",
  "published" : "2022-04-06T00:01:29Z",
  "aliases" : [ "CVE-2020-28847" ],
  "summary" : "Cross site scripting in valine",
  "details" : "valine is a fast, simple & powerful comment system. Cross Site Scripting (XSS) vulnerability in xCss Valine v1.4.14 via the nick parameter to /classes/Comment. A fix was released in version 1.4.15.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "valine"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.15"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-28847"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/xCss/Valine/issues/348"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/xCss/Valine"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/xCss/Valine/releases/tag/v1.4.15"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-04-07T18:16:52Z",
    "nvd_published_at" : "2022-04-05T16:15:00Z"
  }
}