CVE-2021-33913

Severity Score

9.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

libspf2 before 1.2.11 has a heap-based buffer overflow that might allow remote attackers to execute arbitrary code (via an unauthenticated e-mail message from anywhere on the Internet) with a crafted SPF DNS record, because of SPF_record_expand_data in spf_expand.c. The amount of overflowed data depends on the relationship between the length of an entire domain name and the length of its leftmost label. The vulnerable code may be part of the supply chain of a site's e-mail infrastructure (e.g., with additional configuration, Exim can use libspf2; the Postfix web site links to unofficial patches for use of libspf2 with Postfix; older versions of spfquery relied on libspf2) but most often is not.

libspf2 versiones anteriores a 1.2.11, presenta un desbordamiento de búfer en la región heap de la memoria que podría permitir a atacantes remotos ejecutar código arbitrario (por medio de un mensaje de correo electrónico no autenticado desde cualquier lugar de Internet) con un registro DNS SPF diseñado, debido a SPF_record_expand_data en el archivo spf_expand.c. La cantidad de datos desbordados depende de la relación entre la longitud de un nombre de dominio completo y la longitud de su etiqueta más a la izquierda. El código vulnerable puede formar parte de la cadena de suministro de la infraestructura de correo electrónico de un sitio (por ejemplo, con una configuración adicional, Exim puede usar libspf2; el sitio web de Postfix enlaza con parches no oficiales para el uso de libspf2 con Postfix; las versiones más antiguas de spfquery dependían de libspf2), pero lo más frecuente es que no lo sea

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-06-07 CVE Reserved
2022-01-19 CVE Published
2024-08-04 CVE Updated
2024-08-04 First Exploit
2024-10-04 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-787: Out-of-bounds Write

CAPEC

References (4)

URL	Tag	Source
https://github.com/shevek/libspf2/tree/8131fe140704eaae695e76b5cd09e39bd1dd220b	Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/01/msg00015.html	Mailing List

URL	Date	SRC
https://nathanielbennett.com/blog/libspf2-cve-jan-2022-disclosure	2024-08-04

URL	Date	SRC

URL	Date	SRC
https://security.gentoo.org/glsa/202401-22	2024-01-15

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Libspf2 Project Search vendor "Libspf2 Project"		Libspf2 Search vendor "Libspf2 Project" for product "Libspf2"				< 1.2.11 Search vendor "Libspf2 Project" for product "Libspf2" and version " < 1.2.11"		-		Affected