Vulnerability · Published Feb 16, 2023 · Assigned by mozilla

CVE-2021-43529

Critical 9.8

In plain English

A critical-severity out-of-bounds write in Thunderbird from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)0.5%top 59.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	thunderbird	1:91.3.0-1	DEBIAN-CVE-2021-43529
Debian:13	thunderbird	1:91.3.0-1	DEBIAN-CVE-2021-43529
Debian:14	thunderbird	1:91.3.0-1	DEBIAN-CVE-2021-43529
Rocky Linux:8	thunderbird	0:91.3.0-2.el8_4	RLSA-2021:4130
Rocky Linux:8	thunderbird	0:91.3.0-2.el8	RLSA-2021:4130

Affected products (as reported)

Vendor	Product	Versions
Mozilla	Thunderbird	unspecified – before 91.3.0

Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

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