CVE-2024-43367: Boa engine Boa Has An Uncaught Exception Vulnerability

HIGH
Advisory Identifier: GHSA-f67q-wr6w-23jq
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CVSS 7.5
CWE-248
Published
Advisory Summary

CVE-2024-43367 is a HIGH (CVSS 7.5) boa has an uncaught exception vulnerability (CWE-248: Uncaught Exception) affecting Boa engine libraries in the crates.io ecosystem. The issue involves boa has an uncaught exception when transitioning the state of `asyncgenerator` objects. Remediation is available by upgrading affected packages to version 0.19.0.

CVE-2024-43367 at a Glance

CVE Identifier CVE-2024-43367
GHSA Identifier GHSA-f67q-wr6w-23jq
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-248: Uncaught Exception
Affected Product Boa engine
Package Ecosystem crates.io
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2024-43367

To remediate this vulnerability, upgrade all affected Boa 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.

boa_engine fixed: 0.19.0 
Upgrade boa_engine to 0.19.0
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 boa_engine

How to Check if You Are Affected

To determine whether your application is affected by CVE-2024-43367, inspect your project dependencies for Boa engine:

inspect dependencies for boa_engine

Analyze the terminal output to locate any version of Boa engine in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.19.0), 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-248: Uncaught Exception, where an exception is thrown from a function, but it is not caught. In Boa 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

A wrong assumption made when handling ECMAScript's `AsyncGenerator` operations can cause an uncaught exception on certain scripts. ## Details Boa's implementation of `AsyncGenerator` makes the assumption that the state of an `AsyncGenerator` object cannot change while resolving a promise created by methods of `AsyncGenerator` such as `%AsyncGeneratorPrototype%.next`, `%AsyncGeneratorPrototype%.return`, or `%AsyncGeneratorPrototype%.throw`. However, a carefully constructed code could trigger a state transition from a getter method for the promise's `then` property, which causes the engine to fail an assertion of this assumption, causing an uncaught exception. This could be used to create a Denial Of Service attack in applications that run arbitrary ECMAScript code provided by an external user. ## Patches Version 0.19.0 is patched to correctly handle this case. ## Workarounds Users unable to upgrade to the patched version would want to use [`std::panic::catch_unwind`](https://doc.rust-lang.org/std/panic/fn.catch_unwind.html) to ensure any exceptions caused by the engine don't impact the availability of the main application. ## References - https://github.com/boa-dev/boa/commit/69ea2f52ed976934bff588d6b566bae01be313f7 - https://github.com/tc39/ecma262/security/advisories/GHSA-g38c-wh3c-5h9r

CVE-2024-43367 Affected Boa engine Versions

1 component(s)
Fixed Versions:
0.19.0
Product / Package Ecosystem Affected Versions Fixed Version
boa_engine
 crates.io
≥ 0.16
< 0.19.0
0.19.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/boa-dev/boa/security/advisories/GHSA-f67q-wr6w-23jq
GitHub Advisory / Wiki ADVISORY
https://github.com/tc39/ecma262/security/advisories/GHSA-g38c-wh3c-5h9r
NVD — CVE-2024-43367 NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-43367
Security Fix Commit FIX COMMIT
https://github.com/boa-dev/boa/commit/69ea2f52ed976934bff588d6b566bae01be313f7
Boa engine Source Repository REPOSITORY
https://github.com/boa-dev/boa
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2024-0444.html

Frequently Asked Questions

What is CVE-2024-43367?
CVE-2024-43367 is a security vulnerability in Boa engine involving Boa has an uncaught exception when transitioning the state of `AsyncGenerator` objects under CWE-248: Uncaught Exception.
Which Boa engine versions are affected?
Affected versions include releases prior to 0.19.0 across affected packages: boa_engine.
What version fixes CVE-2024-43367?
Upgrading to 0.19.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is boa_engine affected?
Yes, boa_engine is affected in releases prior to 0.19.0. Upgrade your dependency to 0.19.0 or later.
What is the CVSS score of CVE-2024-43367?
CVE-2024-43367 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2024-43367?
CVE-2024-43367 is classified under CWE-248: Uncaught Exception (An exception is thrown from a function, but it is not caught.).
How can I check crates.io dependencies for CVE-2024-43367?
Run the dependency tree command: 'inspect dependencies for boa_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-f67q-wr6w-23jq",
  "modified" : "2025-12-20T05:28:05Z",
  "published" : "2024-08-14T20:49:51Z",
  "aliases" : [ "CVE-2024-43367" ],
  "summary" : "Boa has an uncaught exception when transitioning the state of `AsyncGenerator` objects",
  "details" : "A wrong assumption made when handling ECMAScript's `AsyncGenerator` operations can cause an uncaught exception on certain scripts.\n\n## Details\n\nBoa's implementation of `AsyncGenerator` makes the assumption that the state of an `AsyncGenerator` object cannot change while resolving a promise created by methods of `AsyncGenerator` such as `%AsyncGeneratorPrototype%.next`, `%AsyncGeneratorPrototype%.return`, or `%AsyncGeneratorPrototype%.throw`.\nHowever, a carefully constructed code could trigger a state transition from a getter method for the promise's `then` property, which causes the engine to fail an assertion of this assumption, causing an uncaught exception. This could be used to create a Denial Of Service attack in applications that run arbitrary ECMAScript code provided by an external user.\n\n## Patches\n\nVersion 0.19.0 is patched to correctly handle this case.\n\n## Workarounds\n\nUsers unable to upgrade to the patched version would want to use [`std::panic::catch_unwind`](https://doc.rust-lang.org/std/panic/fn.catch_unwind.html) to ensure any exceptions caused by the engine don't impact the availability of the main application.\n\n## References\n\n- https://github.com/boa-dev/boa/commit/69ea2f52ed976934bff588d6b566bae01be313f7\n- https://github.com/tc39/ecma262/security/advisories/GHSA-g38c-wh3c-5h9r",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "boa_engine"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.16"
      }, {
        "fixed" : "0.19.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/boa-dev/boa/security/advisories/GHSA-f67q-wr6w-23jq"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tc39/ecma262/security/advisories/GHSA-g38c-wh3c-5h9r"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-43367"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/boa-dev/boa/commit/69ea2f52ed976934bff588d6b566bae01be313f7"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/boa-dev/boa"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2024-0444.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-248" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-08-14T20:49:51Z",
    "nvd_published_at" : "2024-08-15T21:15:17Z"
  }
}