Vulnerability in Mozilla Thunderbird
CVE-2021-23993
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.
EPSS: 0.004 (35.0th 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
Weakness classification (CWE)
References
- security@mozilla.org (x_refsource_MISC, Release Notes, Vendor Advisory)
- security@mozilla.org (Permissions Required, x_refsource_MISC, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-23993?
- CVE-2021-23993 is a medium-severity vulnerability in Mozilla Thunderbird, classified under Improper Verification of Cryptographic Signature. CVSS score: 6.5/10. Published 2021-06-24.
- How severe is CVE-2021-23993?
- Medium severity. CVSS v3 base score is 6.5 out of 10.