CVE-2024-43357: ECMA-262 type confusion (CVSS 8.6)

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. 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://bugzilla.mozilla.org/show_bug.cgi?id=1901411 - https://github.com/boa-dev/boa/security/advisories/GHSA-f67q-wr6w-23jq - https://bugs.webkit.org/show_bug.cgi?id=275407 - https://issues.chromium.org/issues/346692561 - https://www.cve.org/CVERecord?id=CVE-2024-7652

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityLow

IntegrityLow

AvailabilityHigh

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

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2024-43357 being actively exploited?

CVE-2024-43357 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.68%.

How severe is CVE-2024-43357?

CVE-2024-43357 has a CVSS 3.1 base score of 8.6, rated high. EPSS estimates a 0.68% probability of exploitation.

How do I fix CVE-2024-43357?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2024-43357 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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