CVE-2021-23991

Mozilla: An attacker may use Thunderbird's OpenPGP key refresh mechanism to poison an existing key

Severity Score

6.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

If a Thunderbird user has previously imported Alice's OpenPGP key, and Alice has extended the validity period of her key, but Alice's updated key has not yet been imported, an attacker may send an email containing a crafted version of Alice's key with an invalid subkey, Thunderbird might subsequently attempt to use the invalid subkey, and will fail to send encrypted email to Alice. This vulnerability affects Thunderbird < 78.9.1.

Si un usuario de Thunderbird ha importado previamente la clave OpenPGP de Alice, y Alice ha ampliado el periodo de validez de su clave, pero la clave actualizada de Alice aún no ha sido importada, un atacante puede enviar un correo electrónico conteniendo una versión diseñada de la clave de Alice con una subclave no válida, Thunderbird podría posteriormente intentar usar la subclave no válida, y producirá un fallo al enviar el correo electrónico cifrado a Alice. Esta vulnerabilidad afecta a Thunderbird versiones anteriores a 78.9.1

*Credits: N/A

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

High

Authentication

None

Confidentiality

Partial

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
2024-08-03 First Exploit
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-347: Improper Verification of Cryptographic Signature

CAPEC

References (4)

URL	Tag	Source

URL	Date	SRC
https://bugzilla.mozilla.org/show_bug.cgi?id=1673240	2024-08-03

URL	Date	SRC

URL	Date	SRC
https://www.mozilla.org/security/advisories/mfsa2021-13	2021-07-08
https://access.redhat.com/security/cve/CVE-2021-23991	2021-04-14
https://bugzilla.redhat.com/show_bug.cgi?id=1948393	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