CVE-2019-0991: Microsoft.ChakraCore Chakra Scripting Engine Out-of-bounds Write Vulnerability

HIGH
Advisory Identifier: GHSA-6973-94v8-5mgw
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CVSS 7.5
CWE-787
Published
Advisory Summary

CVE-2019-0991 is a HIGH (CVSS 7.5) chakra scripting engine out-of-bounds write vulnerability (CWE-787: Out-of-bounds Write) affecting Microsoft.ChakraCore libraries in the NuGet ecosystem. The issue involves chakra scripting engine out-of-bounds write. Remediation is available by upgrading affected packages to version 1.11.10.

CVE-2019-0991 at a Glance

CVE Identifier CVE-2019-0991
GHSA Identifier GHSA-6973-94v8-5mgw
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-787: Out-of-bounds Write
Affected Product Microsoft.ChakraCore
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:H/PR:N/UI:R/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 Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2019-0991

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

Microsoft.ChakraCore fixed: 1.11.10 
Upgrade Microsoft.ChakraCore to 1.11.10
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for Microsoft.ChakraCore

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-0991, inspect your project dependencies for Microsoft.ChakraCore:

inspect dependencies for Microsoft.ChakraCore

Analyze the terminal output to locate any version of Microsoft.ChakraCore in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.11.10), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-787: Out-of-bounds Write, where the product writes data past the end, or before the beginning, of the intended buffer. In Microsoft.ChakraCore, 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

A remote code execution vulnerability exists in the way that the Chakra scripting engine handles objects in memory in Microsoft Edge (HTML-based). The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Microsoft Edge (HTML-based) and then convince a user to view the website. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability. The security update addresses the vulnerability by modifying how the Chakra scripting engine handles objects in memory.

CVE-2019-0991 Affected Microsoft.ChakraCore Versions

1 component(s)
Fixed Versions:
1.11.10
Product / Package Ecosystem Affected Versions Fixed Version
Microsoft.ChakraCore
nuget/Microsoft.ChakraCore
NuGet
< 1.11.10
1.11.10

References

NVD — CVE-2019-0991 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-0991
Security Fix Commit FIX COMMIT
https://github.com/chakra-core/ChakraCore/commit/1caa4118796d33513bc40ce894c053a92de98abb
Security Fix Commit FIX COMMIT
https://github.com/chakra-core/ChakraCore/commit/3d6226cc2d1077537220361c82e34a362c6c76ee
Microsoft.ChakraCore Source Repository REPOSITORY
https://github.com/chakra-core/ChakraCore
msrc.microsoft.com/update-guide/vulner... WEB
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-0991
Microsoft.ChakraCore Security Information SECURITY
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0991

Frequently Asked Questions

What is CVE-2019-0991?
CVE-2019-0991 is a security vulnerability in Microsoft.ChakraCore involving Chakra Scripting Engine Out-of-bounds write under CWE-787: Out-of-bounds Write.
Which Microsoft.ChakraCore versions are affected?
Affected versions include releases prior to 1.11.10 across affected packages: Microsoft.ChakraCore.
What version fixes CVE-2019-0991?
Upgrading to 1.11.10 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Microsoft.ChakraCore affected?
Yes, Microsoft.ChakraCore is affected in releases prior to 1.11.10. Upgrade your dependency to 1.11.10 or later.
What is the CVSS score of CVE-2019-0991?
CVE-2019-0991 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2019-0991?
CVE-2019-0991 is classified under CWE-787: Out-of-bounds Write (The product writes data past the end, or before the beginning, of the intended buffer.).
How can I check NuGet dependencies for CVE-2019-0991?
Run the dependency tree command: 'inspect dependencies for Microsoft.ChakraCore'. 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-6973-94v8-5mgw",
  "modified" : "2025-05-20T20:43:21Z",
  "published" : "2021-03-29T20:57:42Z",
  "aliases" : [ "CVE-2019-0991" ],
  "summary" : "Chakra Scripting Engine Out-of-bounds write",
  "details" : "A remote code execution vulnerability exists in the way that the Chakra scripting engine handles objects in memory in Microsoft Edge (HTML-based). The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Microsoft Edge (HTML-based) and then convince a user to view the website. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability. The security update addresses the vulnerability by modifying how the Chakra scripting engine handles objects in memory.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.ChakraCore"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.11.10"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-0991"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/chakra-core/ChakraCore/commit/1caa4118796d33513bc40ce894c053a92de98abb"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/chakra-core/ChakraCore/commit/3d6226cc2d1077537220361c82e34a362c6c76ee"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/chakra-core/ChakraCore"
  }, {
    "type" : "WEB",
    "url" : "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-0991"
  }, {
    "type" : "WEB",
    "url" : "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0991"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-787" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-03-19T20:42:16Z",
    "nvd_published_at" : "2019-06-12T14:29:00Z"
  }
}