CVE-2024-3853 — A use-after-free could result if a JavaScript realm was in the process of being

A use-after-free could result if a JavaScript realm was in the process of being initialized when a garbage collection started. This vulnerability affects Firefox < 125.

01What is this vulnerability?

A use-after-free could result if a JavaScript realm was in the process of being initialized when a garbage collection started. This vulnerability affects Firefox < 125.

02Affected products

Vendor	Product	Versions
Mozilla	Firefox	unspecified

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2024-04-16T15:14:05.547Z
• Last modified: 2024-10-28T20:47:22.135Z

09References

• bugzilla.mozilla.org — https://bugzilla.mozilla.org/show_bug.cgi?id=1884427
• www.mozilla.org — https://www.mozilla.org/security/advisories/mfsa2024-18/