CVE-2024-43357Network attack vector

Type confusion via reentrant async-generator resolution

Published Aug 15, 2024 · Updated Aug 15, 2024

Type confusion in ECMA-262 2022 through 2024 allows remote attackers to disrupt JavaScript engines through crafted async generators. The async-generator algorithms pass inherited IteratorResult objects to ordinary promise resolvers, letting an Object.prototype then property make those objects thenable and reenter generator machinery before its internal state is safe. Exploitation requires an engine that implemented the defective text, and outcomes are implementation-dependent, including type confusion, pointer dereference, and uncaught exceptions.

CVSS severity8.6
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in ECMA-262 2022 through 2024 allows remote attackers to disrupt JavaScript engines through crafted async generators. The async-generator algorithms pass inherited IteratorResult objects to ordinary promise resolvers, letting an Object.prototype then property make those objects thenable and reenter generator machinery before its internal state is safe. Exploitation requires an engine that implemented the defective text, and outcomes are implementation-dependent, including type confusion, pointer dereference, and uncaught exceptions.

The record

CVE
CVE-2024-43357
Published
Aug 15, 2024
Updated
Aug 15, 2024
Vendor
Ecma International
Product
ECMA-262
Classifications
CWE-476, CWE-843, CWE-248
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2022, < 2025
  2. Affected versionversion=2022 <2025

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Ecma International · ECMA-262version=>= 2022, < 2025; version=2022 <2025

Published CVSS scores

8.6GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
CWE-248Uncaught Exception

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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