CVE intelligence and bounded remediation

CVE-2024-43357 — ECMA-262 is the language specification for the scripting language ECMAScript

High CVSS 8.6

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. The 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. The 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. ## References - https://github.com/tc39/ecma262/commit/1e24a286d0a327d08e1154926b3ee79820232727 - https://bugzill…

Severity
High
CVSS
8.6 (3.1)
Published
2024-08-15
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-248, CWE-476, CWE-843

Affected products

No browser-safe affected-product rows are available.

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

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