Improper Certificate Validation in Cisco AsyncOS for Secure Web Appliance and Cisco AsyncOS for Cisco Email Security Appliance - CVE-2021-1566
Published: June 16, 2021
Vulnerability identifier: #VU54172
CSH Severity: Medium
CVSS v4: 5.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-1566
CWE-ID: CWE-295
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to preform MitM attack.
The vulnerability exists due to improper certificate validation when establishing TLS connection. A remote attacker can perform a man-in-the-middle (MitM) attack.
Affected software
Cisco AsyncOS for Secure Web Appliance
Cisco AsyncOS for Cisco Email Security Appliance
Cisco AsyncOS for Cisco Email Security Appliance
How to mitigate CVE-2021-1566
Install updates from vendor's website.
Cisco AsyncOS for Secure Web Appliance - addressed in versions 11.8.3 021, 12.0.3 005, 12.5.1 043
Cisco AsyncOS for Cisco Email Security Appliance - addressed in versions 12.5.3 035, 13.0.0 030, 13.5.3 010
Cisco AsyncOS for Cisco Email Security Appliance - addressed in versions 12.5.3 035, 13.0.0 030, 13.5.3 010