Vulnerability in Mozilla Thunderbird
CVE-2021-4126
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.
EPSS: 0.004 (35.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.
Affected products
- Mozilla Thunderbird — versions unspecified
References
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Permissions Required, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-4126?
- CVE-2021-4126 is a medium-severity vulnerability in Mozilla Thunderbird. CVSS score: 6.5/10. Published 2022-12-22.
- How severe is CVE-2021-4126?
- Medium severity. CVSS v3 base score is 6.5 out of 10.