CVE-2021-43529

Mozilla Thunderbird and 1 other: Out-of-bounds Write

CVE-2021-43529 is fixed in 7 products on 2 platforms, first by Mozilla Thunderbird (en-US) 91.3.0, released November 1, 2021. It is not reported as exploited. Patch Radar priority: High.

HighFixed on 2 platforms
CVSS
9.8
Important
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0047
40th percentile

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.

Where it's fixed

ProductFixed inFixReleased
Windows apps
Mozilla Thunderbird (en-US) 91.3.0 Mozilla Thunderbird (en-US) 91.3.0 Nov 1, 2021
Linux
thunderbird · Debian 12.15 (bookworm) 1:91.3.0-1 DEBIAN-CVE-2021-43529 Feb 16, 2023
thunderbird · Debian 13.5 (trixie) 1:91.3.0-1 DEBIAN-CVE-2021-43529 Feb 16, 2023
thunderbird · Debian 14 1:91.3.0-1 DEBIAN-CVE-2021-43529 Feb 16, 2023
thunderbird · RHEL 8 0:91.3.0-2.el8_4 RHSA-2021:4130 Nov 4, 2021
thunderbird · Ubuntu 18.04.6 LTS (bionic) 1:91.5.0+build1-0ubuntu0.18.04.1 thunderbird 1:91.5.0+build1-0ubuntu0.18.04.1 Feb 16, 2023
thunderbird · Ubuntu 20.04 LTS (focal) 1:91.5.0+build1-0ubuntu0.20.04.1 thunderbird 1:91.5.0+build1-0ubuntu0.20.04.1 Feb 16, 2023
thunderbird-gnome-support · Ubuntu 18.04.6 LTS (bionic) 1:91.5.0+build1-0ubuntu0.18.04.1 thunderbird-gnome-support 1:91.5.0+build1-0ubuntu0.18.04.1 Feb 16, 2023
thunderbird-gnome-support · Ubuntu 20.04 LTS (focal) 1:91.5.0+build1-0ubuntu0.20.04.1 thunderbird-gnome-support 1:91.5.0+build1-0ubuntu0.20.04.1 Feb 16, 2023
thunderbird-mozsymbols · Ubuntu 18.04.6 LTS (bionic) 1:91.5.0+build1-0ubuntu0.18.04.1 thunderbird-mozsymbols 1:91.5.0+build1-0ubuntu0.18.04.1 Feb 16, 2023
thunderbird-mozsymbols · Ubuntu 20.04 LTS (focal) 1:91.5.0+build1-0ubuntu0.20.04.1 thunderbird-mozsymbols 1:91.5.0+build1-0ubuntu0.20.04.1 Feb 16, 2023
xul-ext-calendar-timezones · Ubuntu 18.04.6 LTS (bionic) 1:91.5.0+build1-0ubuntu0.18.04.1 xul-ext-calendar-timezones 1:91.5.0+build1-0ubuntu0.18.04.1 Feb 16, 2023
xul-ext-calendar-timezones · Ubuntu 20.04 LTS (focal) 1:91.5.0+build1-0ubuntu0.20.04.1 xul-ext-calendar-timezones 1:91.5.0+build1-0ubuntu0.20.04.1 Feb 16, 2023
xul-ext-gdata-provider · Ubuntu 18.04.6 LTS (bionic) 1:91.5.0+build1-0ubuntu0.18.04.1 xul-ext-gdata-provider 1:91.5.0+build1-0ubuntu0.18.04.1 Feb 16, 2023
xul-ext-gdata-provider · Ubuntu 20.04 LTS (focal) 1:91.5.0+build1-0ubuntu0.20.04.1 xul-ext-gdata-provider 1:91.5.0+build1-0ubuntu0.20.04.1 Feb 16, 2023
xul-ext-lightning · Ubuntu 18.04.6 LTS (bionic) 1:91.5.0+build1-0ubuntu0.18.04.1 xul-ext-lightning 1:91.5.0+build1-0ubuntu0.18.04.1 Feb 16, 2023
xul-ext-lightning · Ubuntu 20.04 LTS (focal) 1:91.5.0+build1-0ubuntu0.20.04.1 xul-ext-lightning 1:91.5.0+build1-0ubuntu0.20.04.1 Feb 16, 2023

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