CVE-2021-43540

MEDIUM

Firefox < 95.0 - ServiceWorker Persistence via WebExtension

Title source: llm
STIX 2.1

Description

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.

References (3)

Core 3
Core References
Issue Tracking, Permissions Required, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1636629
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202202-03

Scores

CVSS v3 6.5
EPSS 0.0036
EPSS Percentile 58.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Details

Status published
Products (1)
mozilla/firefox < 95.0
Published Dec 08, 2021
Tracked Since Feb 18, 2026