vulnerability
MFSA2021-13 Thunderbird: Security Vulnerabilities fixed in Thunderbird 78.9.1 (CVE-2021-23993)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 4 | (AV:N/AC:M/Au:N/C:N/I:P/A:N) | Apr 8, 2021 | Apr 9, 2021 | Aug 12, 2025 |
Severity
4
CVSS
(AV:N/AC:M/Au:N/C:N/I:P/A:N)
Published
Apr 8, 2021
Added
Apr 9, 2021
Modified
Aug 12, 2025
Description
An attacker may perform a DoS attack to prevent a user from sending encrypted email to a correspondent. If an attacker creates a crafted OpenPGP key with a subkey that has an invalid self signature, and the Thunderbird user imports the crafted key, then Thunderbird may try to use the invalid subkey, but the RNP library rejects it from being used, causing encryption to fail. This vulnerability affects Thunderbird < 78.9.1.
Solution
mozilla-thunderbird-upgrade-78_9_1
NEW
Explore Exposure Command
Confidently identify and prioritize exposures from endpoint to cloud with full attack surface visibility and threat-aware risk context.