CVE-2019-18413: Class validator Cross-Site Scripting Vulnerability

CRITICAL
Advisory Identifier: GHSA-fj58-h2fr-3pp2
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CVSS 9.8
CWE-89 CWE-79
Published
Advisory Summary

CVE-2019-18413 is a CRITICAL (CVSS 9.8) cross-site scripting vulnerability (CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')) affecting Class validator libraries in the npm ecosystem. The issue involves sql injection and cross-site scripting in class-validator. Remediation is available by upgrading affected packages to version 0.14.0.

CVE-2019-18413 at a Glance

CVE Identifier CVE-2019-18413
GHSA Identifier GHSA-fj58-h2fr-3pp2
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
Affected Product Class validator
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-2019-18413

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

class-validator fixed: 0.14.0 
npm install class-validator@0.14.0
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 class-validator

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2019-18413, inspect your project dependencies using npm:

npm ls class-validator

Analyze the terminal output to locate any version of Class validator in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.14.0), your application is affected.

Note: The npm ls class-validator 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-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection'), where the product constructs all or part of an sql command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended sql command when it is sent to a downstream component. without sufficient removal or quoting of sql syntax in user-controllable inputs, the generated sql query can cause those inputs to be interpreted as sql instead of ordinary user data. In Class validator, 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

In TypeStack class-validator, `validate()` input validation can be bypassed because certain internal attributes can be overwritten via a conflicting name. Even though there is an optional `forbidUnknownValues` parameter that can be used to reduce the risk of this bypass, this option is not documented and thus most developers configure input validation in the vulnerable default manner. With this vulnerability, attackers can launch SQL Injection or XSS attacks by injecting arbitrary malicious input. The default settings for `forbidUnknownValues` has been changed to `true` in 0.14.0. NOTE: a software maintainer agrees with the "is not documented" finding but suggests that much of the responsibility for the risk lies in a different product.

CVE-2019-18413 Affected Class validator Versions

1 component(s)
Fixed Versions:
0.14.0
Product / Package Ecosystem Affected Versions Fixed Version
class-validator
npm/class-validator
npm
< 0.14.0
0.14.0

References

NVD — CVE-2019-18413 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-18413
Class validator Source Repository REPOSITORY
https://github.com/typestack/class-validator/issues/1422#issuecomment-1344635415
Class validator Source Repository REPOSITORY
https://github.com/typestack/class-validator/issues/438
Class validator Source Repository REPOSITORY
https://github.com/typestack/class-validator/issues/438#issuecomment-964728471
Class validator Source Repository REPOSITORY
https://github.com/typestack/class-validator/pull/1798
Class validator Source Repository REPOSITORY
https://github.com/typestack/class-validator
Class validator Source Repository REPOSITORY
https://github.com/typestack/class-validator#passing-options

Frequently Asked Questions

What is CVE-2019-18413?
CVE-2019-18413 is a security vulnerability in Class validator involving SQL Injection and Cross-site Scripting in class-validator under CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection').
Which Class validator versions are affected?
Affected versions include releases prior to 0.14.0 across affected packages: class-validator.
What version fixes CVE-2019-18413?
Upgrading to 0.14.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is class-validator affected?
Yes, class-validator is affected in releases prior to 0.14.0. Upgrade your dependency to 0.14.0 or later.
What is the CVSS score of CVE-2019-18413?
CVE-2019-18413 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-2019-18413?
CVE-2019-18413 is classified under CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') (The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.).
How can I check npm dependencies for CVE-2019-18413?
Run the dependency tree command: 'npm ls class-validator'. 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-fj58-h2fr-3pp2",
  "modified" : "2023-01-11T21:59:18Z",
  "published" : "2021-10-12T16:35:45Z",
  "aliases" : [ "CVE-2019-18413" ],
  "summary" : "SQL Injection and Cross-site Scripting in class-validator",
  "details" : "In TypeStack class-validator, `validate()` input validation can be bypassed because certain internal attributes can be overwritten via a conflicting name. Even though there is an optional `forbidUnknownValues` parameter that can be used to reduce the risk of this bypass, this option is not documented and thus most developers configure input validation in the vulnerable default manner. With this vulnerability, attackers can launch SQL Injection or XSS attacks by injecting arbitrary malicious input.\n\nThe default settings for `forbidUnknownValues` has been changed to `true` in 0.14.0.\n\nNOTE: a software maintainer agrees with the \"is not documented\" finding but suggests that much of the responsibility for the risk lies in a different product.",
  "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" : "class-validator"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.14.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-18413"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/typestack/class-validator/issues/1422#issuecomment-1344635415"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/typestack/class-validator/issues/438"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/typestack/class-validator/issues/438#issuecomment-964728471"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/typestack/class-validator/pull/1798"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/typestack/class-validator"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/typestack/class-validator#passing-options"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79", "CWE-89" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-10-08T23:11:08Z",
    "nvd_published_at" : "2019-10-24T18:15:00Z"
  }
}