{"cve":"CVE-2024-43357","nvd":{"published":"2024-08-15T19:15:20.107","modified":"2026-06-17T07:50:52.753","status":"Deferred","description":"ECMA-262 is the language specification for the scripting language ECMAScript. A problem in the ECMAScript (JavaScript) specification of async generators, introduced by a May 2021 spec refactor, may lead to mis-implementation in a way that could present as a security vulnerability, such as type confusion and pointer dereference.\n\nThe internal async generator machinery calls regular promise resolver functions on IteratorResult (`{ done, value }`) objects that it creates, assuming that the IteratorResult objects will not be then-ables. Unfortunately, these IteratorResult objects inherit from `Object.prototype`, so these IteratorResult objects can be made then-able, triggering arbitrary behaviour, including re-entering the async generator machinery in a way that violates some internal invariants.\n\nThe ECMAScript specification is a living standard and the issue has been addressed at the time of this advisory's public disclosure. JavaScript engine implementors should refer to the latest specification and update their implementations to comply with the `AsyncGenerator` section.\n\n## References\n\n- https://github.com/tc39/ecma262/commit/1e24a286d0a327d08e1154926b3ee79820232727\n- https://bugzilla.mozilla.org/show_bug.cgi?id=1901411\n- https://github.com/boa-dev/boa/security/advisories/GHSA-f67q-wr6w-23jq\n- https://bugs.webkit.org/show_bug.cgi?id=275407\n- https://issues.chromium.org/issues/346692561\n- https://www.cve.org/CVERecord?id=CVE-2024-7652","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H","score":8.6},"cwes":["CWE-248","CWE-476","CWE-843"],"references":["https://bugs.webkit.org/show_bug.cgi?id=275407","https://bugzilla.mozilla.org/show_bug.cgi?id=1901411","https://github.com/boa-dev/boa/security/advisories/GHSA-f67q-wr6w-23jq","https://github.com/tc39/ecma262/commit/1e24a286d0a327d08e1154926b3ee79820232727","https://github.com/tc39/ecma262/commit/4cb5a6980e20be76c648f113c4cc762342172df3"],"products":[],"source":"nvd","synced_at":"2026-10-19T21:54:16.205165117+00:00"},"epss":{"cve":"CVE-2024-43357","score":0.00679,"percentile":0.52382,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}