CVE-2021-34801: Valine Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-p2c4-gxp4-j3xp
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CVSS 5.3
CWE-94
Published
Advisory Summary

CVE-2021-34801 is a MODERATE (CVSS 5.3) denial of service vulnerability (CWE-94: Improper Control of Generation of Code ('Code Injection')) affecting Valine libraries in the npm ecosystem. The issue involves denial of service in valine. Remediation is available in the latest vendor maintenance releases.

CVE-2021-34801 at a Glance

CVE Identifier CVE-2021-34801
GHSA Identifier GHSA-p2c4-gxp4-j3xp
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-94: Improper Control of Generation of Code ('Code Injection')
Affected Product Valine
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.3

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:N/I:N/A:L).

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 None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2021-34801

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: Latest secure release 
npm install valine@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 valine

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2021-34801, 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 the patched release), 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-94: Improper Control of Generation of Code ('Code Injection'), where the product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. 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. Valine 1.4.14 allows remote attackers to cause a denial of service (application outage) by supplying a ua (aka User-Agent) value that only specifies the product and version.

CVE-2021-34801 Affected Valine Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
valine
npm/valine
npm
≤ 1.4.14

References

NVD — CVE-2021-34801 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-34801
Valine Source Repository REPOSITORY
https://github.com/xCss/Valine/issues/366
Valine Source Repository REPOSITORY
https://github.com/xCss/Valine

Frequently Asked Questions

What is CVE-2021-34801?
CVE-2021-34801 is a security vulnerability in Valine involving Denial of service in Valine under CWE-94: Improper Control of Generation of Code ('Code Injection').
Which Valine versions are affected?
Affected versions include releases prior to current release patches across affected packages: valine.
What version fixes CVE-2021-34801?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is valine affected?
Yes, valine 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-2021-34801?
CVE-2021-34801 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2021-34801?
CVE-2021-34801 is classified under CWE-94: Improper Control of Generation of Code ('Code Injection') (The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.).
How can I check npm dependencies for CVE-2021-34801?
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-p2c4-gxp4-j3xp",
  "modified" : "2022-05-04T03:11:25Z",
  "published" : "2021-06-21T17:11:25Z",
  "aliases" : [ "CVE-2021-34801" ],
  "summary" : "Denial of service in Valine",
  "details" : "Valine is a fast, simple & powerful comment system. Valine 1.4.14 allows remote attackers to cause a denial of service (application outage) by supplying a ua (aka User-Agent) value that only specifies the product and version.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "valine"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.4.14"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-34801"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/xCss/Valine/issues/366"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/xCss/Valine"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-06-17T18:44:36Z",
    "nvd_published_at" : "2021-06-16T15:15:00Z"
  }
}