CVE-2021-23978

Description

Mozilla developers reported memory safety bugs present in Firefox 85 and Firefox ESR 78.7. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

Category

8.8
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.76% Top 30%
Vendor Advisory debian.org Vendor Advisory gentoo.org Vendor Advisory gentoo.org 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/mfsa2021-07/ release notes vendor advisory
https://www.mozilla.org/security/advisories/mfsa2021-09/ release notes vendor advisory
https://www.mozilla.org/security/advisories/mfsa2021-08/ release notes vendor advisory
https://bugzilla.mozilla.org/buglist.cgi?bug_id=786797%2C1682928%2C1687391%2C1687597 vendor advisory broken link issue tracking
https://lists.debian.org/debian-lts-announce/2021/03/msg00000.html third party advisory mailing list
https://www.debian.org/security/2021/dsa-4866 third party advisory vendor advisory
https://security.gentoo.org/glsa/202104-10 third party advisory vendor advisory
https://security.gentoo.org/glsa/202104-09 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-23978?
CVE-2021-23978 has been scored as a high severity vulnerability.
How to fix CVE-2021-23978?
To fix CVE-2021-23978, 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-2021-23978 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-23978 is being actively exploited. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-23978?
CVE-2021-23978 affects Mozilla Firefox, Mozilla Thunderbird, Mozilla Firefox ESR.
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