CVE-2021-43540
Medium
Published: 08 December 2021
Published
08 December 2021
Modified
21 November 2024
KEV Added
—
Patch
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CVSS Score v3.1
6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
EPSS Score
0.0036
58.7th percentile
Risk Priority
13
60% EPSS · 20% KEV · 20% CVSS
Summary
CVE-2021-43540 is a medium-severity an unspecified weakness vulnerability in Mozilla Firefox. Its CVSS base score is 6.5 (Medium).
Operationally, ranked in the top 41.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-30469
Vulnerability details
WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension. This vulnerability affects Firefox < 95.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
mozilla
firefox
≤ 95.0
Mitigating Controls
No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.