VULNERABILITY INTELLIGENCE

CVE-2021-23993

CVSS score6.5 MEDIUM
EPSS probability0.42%
CISA KEVNot currently listed
Published2021-06-24
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

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.

Weakness classification

  • nvd@nist.gov: CWE-347

Primary references