Cyber Resilience

CVE-2021-23995

High

Published: 24 June 2021

Published
24 June 2021
Modified
21 November 2024
KEV Added
—
Patch
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CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0076 73.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-23995 is a high-severity Operation on a Resource after Expiration or Release (CWE-672) vulnerability in Mozilla Firefox. Its CVSS base score is 8.8 (High).

Operationally, ranked in the top 26.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

When Responsive Design Mode was enabled, it used references to objects that were previously freed. We presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10,…

more

and Firefox < 88.

CWE(s)
CWE-672

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

mozilla
firefox
≤ 88.0
mozilla
firefox esr
≤ 78.10
mozilla
thunderbird
≤ 78.10

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References