CVE-2021-43540

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.

6.5

CVSS

Severity: Medium

CVSS 3.1 •

CVSS 2.0 •

EPSS 0.36%

Vendor Advisory gentoo.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org

Affected: Mozilla Firefox

References

Link	Tags
https://www.mozilla.org/security/advisories/mfsa2021-52/	vendor advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1636629	issue tracking permissions required vendor advisory
https://security.gentoo.org/glsa/202202-03	third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-43540?: CVE-2021-43540 has been scored as a medium severity vulnerability.
How to fix CVE-2021-43540?: To fix CVE-2021-43540, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-43540 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2021-43540 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-43540?: CVE-2021-43540 affects Mozilla Firefox.

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