Buffer overflow in Mozilla Thunderbird

CVE-2021-43529

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.

Vulnerability class: Buffer Overflow

EPSS: 0.005 (38.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-43529?
CVE-2021-43529 is a critical-severity vulnerability in Mozilla Thunderbird, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2023-02-16.
How severe is CVE-2021-43529?
Critical severity. CVSS v3 base score is 9.8 out of 10.