CVE-2021-1566 HIGH

CVE-2021-1566: Cisco Email Security Appliance and Cisco Web Security Appliance Certificate Validation Vulnerability

Vendor Cisco
Product Cisco Web Security Appliance (WSA)
Weakness CWE-296
Published June 16, 2021
Last update November 7, 2024

CVSS base score

7.4/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

June 16, 2021 CVE published
November 7, 2024 Record updated