CVE-2021-1566

Cisco Email Security Appliance and Cisco Web Security Appliance Certificate Validation Vulnerability

Severity Score

7.4

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

A vulnerability in the Cisco Advanced Malware Protection (AMP) for Endpoints integration of Cisco AsyncOS for Cisco Email Security Appliance (ESA) and Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to intercept traffic between an affected device and the AMP servers. This vulnerability is due to improper certificate validation when an affected device establishes TLS connections. A man-in-the-middle attacker could exploit this vulnerability by sending a crafted TLS packet to an affected device. A successful exploit could allow the attacker to spoof a trusted host and then extract sensitive information or alter certain API requests.

Una vulnerabilidad en la integración de Cisco Advanced Malware Protection (AMP) for Endpoints de Cisco AsyncOS para Cisco Email Security Appliance (ESA) y Cisco Web Security Appliance (WSA) podría permitir a un atacante remoto no autenticado interceptar el tráfico entre un dispositivo afectado y los servidores AMP. Esta vulnerabilidad es debido a una comprobación inapropiada del certificado cuando un dispositivo afectado establece conexiones TLS. Un atacante tipo "man-in-the-middle" podría explotar esta vulnerabilidad mediante el envio de un paquete TLS diseñado a un dispositivo afectado. Una explotación con éxito podría permitir al atacante falsificar un host confiable y luego extraer información confidencial o alterar determinadas peticiones de la API

*Credits: N/A

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-11-13 CVE Reserved
2021-06-16 CVE Published
2024-06-19 EPSS Updated
2024-09-17 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-295: Improper Certificate Validation
CWE-296: Improper Following of a Certificate's Chain of Trust

CAPEC

References (1)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-wsa-cert-vali-n8L97RW	2023-11-07

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Cisco Search vendor "Cisco"		Email Security Appliance Search vendor "Cisco" for product "Email Security Appliance"				-		-		Affected
Cisco Search vendor "Cisco"		Asyncos Search vendor "Cisco" for product "Asyncos"				< 12.5.3-035 Search vendor "Cisco" for product "Asyncos" and version " < 12.5.3-035"		-		Affected
Cisco Search vendor "Cisco"		Email Security Appliance Search vendor "Cisco" for product "Email Security Appliance"				-		-		Affected
Cisco Search vendor "Cisco"		Asyncos Search vendor "Cisco" for product "Asyncos"				>= 13.0 < 13.0.0-030 Search vendor "Cisco" for product "Asyncos" and version " >= 13.0 < 13.0.0-030"		-		Affected
Cisco Search vendor "Cisco"		Email Security Appliance Search vendor "Cisco" for product "Email Security Appliance"				-		-		Affected
Cisco Search vendor "Cisco"		Asyncos Search vendor "Cisco" for product "Asyncos"				>= 13.5 < 13.5.3-010 Search vendor "Cisco" for product "Asyncos" and version " >= 13.5 < 13.5.3-010"		-		Affected
Cisco Search vendor "Cisco"		Web Security Appliance Search vendor "Cisco" for product "Web Security Appliance"				-		-		Affected
Cisco Search vendor "Cisco"		Asyncos Search vendor "Cisco" for product "Asyncos"				< 11.8.3-021 Search vendor "Cisco" for product "Asyncos" and version " < 11.8.3-021"		-		Affected
Cisco Search vendor "Cisco"		Web Security Appliance Search vendor "Cisco" for product "Web Security Appliance"				-		-		Affected
Cisco Search vendor "Cisco"		Asyncos Search vendor "Cisco" for product "Asyncos"				>= 12.0.0 < 12.0.3-005 Search vendor "Cisco" for product "Asyncos" and version " >= 12.0.0 < 12.0.3-005"		-		Affected
Cisco Search vendor "Cisco"		Web Security Appliance Search vendor "Cisco" for product "Web Security Appliance"				-		-		Affected
Cisco Search vendor "Cisco"		Asyncos Search vendor "Cisco" for product "Asyncos"				>= 12.5.0 < 12.5.1-043 Search vendor "Cisco" for product "Asyncos" and version " >= 12.5.0 < 12.5.1-043"		-		Affected