CVE-2021-20235

Severity Score

8.1

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

There's a flaw in the zeromq server in versions before 4.3.3 in src/decoder_allocators.hpp. The decoder static allocator could have its sized changed, but the buffer would remain the same as it is a static buffer. A remote, unauthenticated attacker who sends a crafted request to the zeromq server could trigger a buffer overflow WRITE of arbitrary data if CURVE/ZAP authentication is not enabled. The greatest impact of this flaw is to application availability, data integrity, and confidentiality.

Se presenta un fallo en el servidor zeromq en versiones anteriores a 4.3.3, en el archivo src/decoder_allocators.hpp. Se podría cambiar el tamaño del asignador estático del decodificador, pero el búfer permanecería igual, ya que es un búfer estático. Un atacante no autenticado remoto que envía una petición diseñada al servidor zeromq podría desencadenar un desbordamiento del búfer WRITE de datos arbitrarios si la autenticación CURVE/ZAP no está habilitada. El mayor impacto de este fallo es la disponibilidad de la aplicación, la integridad de los datos y la confidencialidad.

*Credits: N/A

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-12-17 CVE Reserved
2021-04-01 CVE Published
2024-03-20 EPSS Updated
2024-08-03 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-787: Out-of-bounds Write

CAPEC

References (2)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC
https://bugzilla.redhat.com/show_bug.cgi?id=1921983	2023-11-07
https://github.com/zeromq/libzmq/security/advisories/GHSA-fc3w-qxf5-7hp6	2023-11-07

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Zeromq Search vendor "Zeromq"		Libzmq Search vendor "Zeromq" for product "Libzmq"				>= 4.2.0 < 4.3.3 Search vendor "Zeromq" for product "Libzmq" and version " >= 4.2.0 < 4.3.3"		-		Affected