CVE-2021-23993

Mozilla: Inability to send encrypted OpenPGP email after importing a crafted OpenPGP key

Severity Score

6.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

Un atacante puede llevar a cabo un ataque DoS para impedir a un usuario de enviar un correo electrónico cifrado a un corresponsal. Si un atacante crea una clave OpenPGP diseñada con una subclave que presenta una autofirma no válida, y el usuario de Thunderbird importa la clave diseñada, entonces Thunderbird puede intentar usar la subclave no válida, pero la biblioteca RNP lo rechaza para ser usado, causando que el cifrado presente un fallo. Esta vulnerabilidad afecta a Thunderbird versiones anteriores a 78.9.1

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-01-13 CVE Reserved
2021-04-14 CVE Published
2024-03-09 EPSS Updated
2024-08-03 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-347: Improper Verification of Cryptographic Signature

CAPEC

References (3)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.mozilla.org/security/advisories/mfsa2021-13	2023-08-08
https://access.redhat.com/security/cve/CVE-2021-23993	2021-04-14
https://bugzilla.redhat.com/show_bug.cgi?id=1948395	2021-04-14

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Mozilla Search vendor "Mozilla"		Thunderbird Search vendor "Mozilla" for product "Thunderbird"				< 78.9.1 Search vendor "Mozilla" for product "Thunderbird" and version " < 78.9.1"		-		Affected