CVE-2021-23954

Description

Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion, leading to a memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

Category

8.8
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.30%
Vendor Advisory mozilla.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org Vendor Advisory mozilla.org
Affected: Mozilla Firefox
Affected: Mozilla Thunderbird
Affected: Mozilla Firefox ESR
Published at:
Updated at:

References

Link Tags
https://www.mozilla.org/security/advisories/mfsa2021-03/ release notes vendor advisory
https://www.mozilla.org/security/advisories/mfsa2021-04/ release notes vendor advisory
https://www.mozilla.org/security/advisories/mfsa2021-05/ release notes vendor advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1684020 issue tracking permissions required vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-23954?
CVE-2021-23954 has been scored as a high severity vulnerability.
How to fix CVE-2021-23954?
To fix CVE-2021-23954, 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-2021-23954 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-23954 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-2021-23954?
CVE-2021-23954 affects Mozilla Firefox, Mozilla Thunderbird, Mozilla Firefox ESR.
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