CVE-2021-4126

22.12.2022, 20:15

When receiving an OpenPGP/MIME signed email message that contains an additional outer MIME message layer, for example a message footer added by a mailing list gateway, Thunderbird only considered the inner signed message for the signature validity. This gave the false impression that the additional contents were also covered by the digital signature. Starting with Thunderbird version 91.4.1, only the signature that belongs to the top level MIME part will be considered for the displayed status. This vulnerability affects Thunderbird < 91.4.1.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	6.5 MEDIUM	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Base Score

CVSS 3.x

EPSS Score

Percentile: 43%

Affected Products (NVD)

Vendor	Product	Version
mozilla	thunderbird	𝑥 < 91.4.1

𝑥

= Vulnerable software versions

Debian Releases

Debian Product

Codename

thunderbird

bookworm	1:115.12.0-1~deb12u1 fixed
bookworm (security)	1:115.16.0esr-1~deb12u1 fixed
bullseye	1:115.12.0-1~deb11u1 fixed
bullseye (security)	1:128.4.0esr-1~deb11u1 fixed
sid	1:128.4.0esr-1 fixed
trixie	1:128.4.0esr-1 fixed

Ubuntu Releases

Ubuntu Product

Codename

thunderbird

bionic	Fixed 1:91.5.0+build1-0ubuntu0.18.04.1 released
focal	Fixed 1:91.5.0+build1-0ubuntu0.20.04.1 released
hirsute	ignored
impish	Fixed 1:91.5.0+build1-0ubuntu0.21.10.1 released
jammy	Fixed 1:91.5.0+build1-0ubuntu1 released
kinetic	Fixed 1:91.5.0+build1-0ubuntu1 released
lunar	Fixed 1:91.5.0+build1-0ubuntu1 released
trusty	ignored
xenial	ignored

openSUSE / SLES Releases

openSUSE Product

Release

MozillaThunderbird

suse enterprise desktop 15 SP3	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP4	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP5	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP6	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP7	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP3	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP4	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP5	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP6	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP7	91.4.1-8.48.1 fixed
suse enterprise server 15 SP3	91.4.1-8.48.1 fixed
suse enterprise server 15 SP4	91.4.1-8.48.1 fixed
suse enterprise server 15 SP5	91.4.1-8.48.1 fixed
suse enterprise server 15 SP6	91.4.1-8.48.1 fixed
suse enterprise server 15 SP7	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP3	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP4	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP5	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP6	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP7	91.4.1-8.48.1 fixed

MozillaThunderbird-translations-common

suse enterprise desktop 15 SP3	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP4	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP5	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP6	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP7	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP3	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP4	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP5	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP6	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP7	91.4.1-8.48.1 fixed
suse enterprise server 15 SP3	91.4.1-8.48.1 fixed
suse enterprise server 15 SP4	91.4.1-8.48.1 fixed
suse enterprise server 15 SP5	91.4.1-8.48.1 fixed
suse enterprise server 15 SP6	91.4.1-8.48.1 fixed
suse enterprise server 15 SP7	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP3	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP4	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP5	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP6	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP7	91.4.1-8.48.1 fixed

MozillaThunderbird-translations-other

suse enterprise desktop 15 SP3	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP4	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP5	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP6	91.4.1-8.48.1 fixed
suse enterprise desktop 15 SP7	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP3	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP4	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP5	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP6	91.4.1-8.48.1 fixed
suse enterprise sap 15 SP7	91.4.1-8.48.1 fixed
suse enterprise server 15 SP3	91.4.1-8.48.1 fixed
suse enterprise server 15 SP4	91.4.1-8.48.1 fixed
suse enterprise server 15 SP5	91.4.1-8.48.1 fixed
suse enterprise server 15 SP6	91.4.1-8.48.1 fixed
suse enterprise server 15 SP7	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP3	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP4	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP5	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP6	91.4.1-8.48.1 fixed
suse enterprise workstation 15 SP7	91.4.1-8.48.1 fixed

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1732310

https://www.mozilla.org/security/advisories/mfsa2021-55/

https://bugzilla.mozilla.org/show_bug.cgi?id=1732310

https://www.mozilla.org/security/advisories/mfsa2021-55/