CVE-2020-1913: Hermes engine Signed To Unsigned Conversion Error Vulnerability

HIGH
Advisory Identifier: GHSA-gmpm-xp43-f7g6
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CVSS 8.1
CWE-681 CWE-195
Published
Advisory Summary

CVE-2020-1913 is a HIGH (CVSS 8.1) signed to unsigned conversion error vulnerability (CWE-681: Incorrect Conversion between Numeric Types) affecting Hermes engine libraries in the npm ecosystem. The issue involves signed to unsigned conversion error in facebook hermes. Remediation is available by upgrading affected packages to version 0.5.2.

CVE-2020-1913 at a Glance

CVE Identifier CVE-2020-1913
GHSA Identifier GHSA-gmpm-xp43-f7g6
Severity HIGH
CVSS v3.1 Base Score 8.1
CWE Classification CWE-681: Incorrect Conversion between Numeric Types
Affected Product Hermes engine
Package Ecosystem npm
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:3.1/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-2020-1913

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

hermes-engine fixed: 0.5.2 
npm install hermes-engine@0.5.2
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 hermes-engine

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2020-1913, inspect your project dependencies using npm:

npm ls hermes-engine

Analyze the terminal output to locate any version of Hermes engine in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.5.2), your application is affected.

Note: The npm ls hermes-engine 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-681: Incorrect Conversion between Numeric Types, where when converting from one data type to another, such as long to integer, data can be omitted or translated in a way that produces unexpected values. if the resulting values are used in a sensitive context, then dangerous behaviors may occur. In Hermes engine, 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

An Integer signedness error in the JavaScript Interpreter in Facebook Hermes prior to commit 2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6 allows attackers to cause a denial of service attack or a potential RCE via crafted JavaScript. Note that this is only exploitable if the application using Hermes permits evaluation of untrusted JavaScript. Hence, most React Native applications are not affected.

CVE-2020-1913 Affected Hermes engine Versions

1 component(s)
Fixed Versions:
0.5.2
Product / Package Ecosystem Affected Versions Fixed Version
hermes-engine
npm/hermes-engine
npm
< 0.5.2
0.5.2

References

NVD — CVE-2020-1913 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-1913
Security Fix Commit FIX COMMIT
https://github.com/facebook/hermes/commit/2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6
Hermes engine Security Information SECURITY
https://www.facebook.com/security/advisories/cve-2020-1913

Frequently Asked Questions

What is CVE-2020-1913?
CVE-2020-1913 is a security vulnerability in Hermes engine involving Signed to Unsigned Conversion Error in Facebook Hermes under CWE-681: Incorrect Conversion between Numeric Types.
Which Hermes engine versions are affected?
Affected versions include releases prior to 0.5.2 across affected packages: hermes-engine.
What version fixes CVE-2020-1913?
Upgrading to 0.5.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is hermes-engine affected?
Yes, hermes-engine is affected in releases prior to 0.5.2. Upgrade your dependency to 0.5.2 or later.
What is the CVSS score of CVE-2020-1913?
CVE-2020-1913 has a CVSS v3.1 base score of 8.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2020-1913?
CVE-2020-1913 is classified under CWE-681: Incorrect Conversion between Numeric Types (When converting from one data type to another, such as long to integer, data can be omitted or translated in a way that produces unexpected values. If the resulting values are used in a sensitive context, then dangerous behaviors may occur.).
How can I check npm dependencies for CVE-2020-1913?
Run the dependency tree command: 'npm ls hermes-engine'. 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-gmpm-xp43-f7g6",
  "modified" : "2022-06-24T01:23:39Z",
  "published" : "2022-05-24T17:27:39Z",
  "aliases" : [ "CVE-2020-1913" ],
  "summary" : "Signed to Unsigned Conversion Error in Facebook Hermes",
  "details" : "An Integer signedness error in the JavaScript Interpreter in Facebook Hermes prior to commit 2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6 allows attackers to cause a denial of service attack or a potential RCE via crafted JavaScript. Note that this is only exploitable if the application using Hermes permits evaluation of untrusted JavaScript. Hence, most React Native applications are not affected.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "hermes-engine"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.5.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.4.3"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-1913"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/facebook/hermes/commit/2c7af7ec481ceffd0d14ce2d7c045e475fd71dc6"
  }, {
    "type" : "WEB",
    "url" : "https://www.facebook.com/security/advisories/cve-2020-1913"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-195", "CWE-681" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-06-24T01:23:39Z",
    "nvd_published_at" : "2020-09-09T19:15:00Z"
  }
}