CVE-2020-1912: Hermes engine Out-of-bounds Read And Out-of-bounds Write Vulnerability

HIGH
Advisory Identifier: GHSA-pf27-929j-9pmm
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CVSS 8.1
CWE-125 CWE-787
Published
Advisory Summary

CVE-2020-1912 is a HIGH (CVSS 8.1) out-of-bounds read and out-of-bounds write vulnerability (CWE-125: Out-of-bounds Read) affecting Hermes engine libraries in the npm ecosystem. The issue involves out-of-bounds read and out-of-bounds write in facebook hermes. Remediation is available by upgrading affected packages to version 0.5.2.

CVE-2020-1912 at a Glance

CVE Identifier CVE-2020-1912
GHSA Identifier GHSA-pf27-929j-9pmm
Severity HIGH
CVSS v3.1 Base Score 8.1
CWE Classification CWE-125: Out-of-bounds Read
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-2020-1912

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-2020-1912, 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-125: Out-of-bounds Read, where the product reads data past the end, or before the beginning, of the intended buffer. 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 out-of-bounds read/write vulnerability when executing lazily compiled inner generator functions in Facebook Hermes prior to commit 091835377369c8fd5917d9b87acffa721ad2a168 allows attackers to potentially execute arbitrary code 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-2020-1912 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-2020-1912 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-1912
Security Fix Commit FIX COMMIT
https://github.com/facebook/hermes/commit/091835377369c8fd5917d9b87acffa721ad2a168
Hermes engine Security Information SECURITY
https://www.facebook.com/security/advisories/cve-2020-1912

Frequently Asked Questions

What is CVE-2020-1912?
CVE-2020-1912 is a security vulnerability in Hermes engine involving Out-of-bounds Read and Out-of-bounds Write in Facebook Hermes under CWE-125: Out-of-bounds Read.
Which Hermes engine versions are affected?
Affected versions include releases prior to 0.5.2 across affected packages: hermes-engine.
What version fixes CVE-2020-1912?
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-2020-1912?
CVE-2020-1912 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-2020-1912?
CVE-2020-1912 is classified under CWE-125: Out-of-bounds Read (The product reads data past the end, or before the beginning, of the intended buffer.).
How can I check npm dependencies for CVE-2020-1912?
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-pf27-929j-9pmm",
  "modified" : "2022-06-24T01:23:52Z",
  "published" : "2022-05-24T17:27:38Z",
  "aliases" : [ "CVE-2020-1912" ],
  "summary" : "Out-of-bounds Read and Out-of-bounds Write in Facebook Hermes",
  "details" : "An out-of-bounds read/write vulnerability when executing lazily compiled inner generator functions in Facebook Hermes prior to commit 091835377369c8fd5917d9b87acffa721ad2a168 allows attackers to potentially execute arbitrary code 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-2020-1912"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/facebook/hermes/commit/091835377369c8fd5917d9b87acffa721ad2a168"
  }, {
    "type" : "WEB",
    "url" : "https://www.facebook.com/security/advisories/cve-2020-1912"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-125", "CWE-787" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-06-24T01:23:52Z",
    "nvd_published_at" : "2020-09-09T19:15:00Z"
  }
}