CVE-2021-43529

Description

Thunderbird versions prior to 91.3.0 are vulnerable to the heap overflow described in CVE-2021-43527 when processing S/MIME messages. Thunderbird versions 91.3.0 and later will not call the vulnerable code when processing S/MIME messages that contain certificates with DER-encoded DSA or RSA-PSS signatures.

Category

9.8
CVSS
Severity: Critical
CVSS 3.1 •
EPSS 0.10%
Affected: Mozilla Thunderbird
Published at:
Updated at:

References

Link Tags
https://bugzilla.mozilla.org/show_bug.cgi?id=CVE-2021-43529 issue tracking

Frequently Asked Questions

What is the severity of CVE-2021-43529?
CVE-2021-43529 has been scored as a critical severity vulnerability.
How to fix CVE-2021-43529?
To fix CVE-2021-43529, 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-2021-43529 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-43529 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-2021-43529?
CVE-2021-43529 affects Mozilla Thunderbird.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.