CVE-2021-23993

MEDIUM

Thunderbird < 78.9.1 - Denial of Service via Crafted OpenPGP Key with Invalid Subkey Self Signature

Title source: llm
STIX 2.1

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.

References (2)

Core 2
Core References
Release Notes, Vendor Advisory x_refsource_misc
https://www.mozilla.org/security/advisories/mfsa2021-13/
Issue Tracking, Permissions Required, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1666360

Scores

CVSS v3 6.5
EPSS 0.0006
EPSS Percentile 20.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Details

CWE
CWE-347
Status published
Products (1)
mozilla/thunderbird < 78.9.1
Published Jun 24, 2021
Tracked Since Feb 18, 2026