CVE-2021-23991

MEDIUM

Thunderbird < 78.9.1 - Info Disclosure

Title source: llm
STIX 2.1

Description

If a Thunderbird user has previously imported Alice's OpenPGP key, and Alice has extended the validity period of her key, but Alice's updated key has not yet been imported, an attacker may send an email containing a crafted version of Alice's key with an invalid subkey, Thunderbird might subsequently attempt to use the invalid subkey, and will fail to send encrypted email to Alice. This vulnerability affects Thunderbird < 78.9.1.

References (2)

Core 2
Core References
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-13/
Exploit, Issue Tracking, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1673240

Scores

CVSS v3 6.8
EPSS 0.0020
EPSS Percentile 42.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Details

Status published
Products (1)
mozilla/thunderbird < 78.9.1
Published Jun 24, 2021
Tracked Since Feb 18, 2026