Vulnerability identifier: #VU54172

Vulnerability risk: Medium

CVSSv3.1: 5.5 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-1566

CWE-ID: CWE-295

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Cisco AsyncOS for Web Security Appliances
Server applications / IDS/IPS systems, Firewalls and proxy servers
Cisco AsyncOS for Cisco Email Security Appliance
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor:

Description

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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-wsa-cert-vali-n8L97RW
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvw08342
http://bst.cloudapps.cisco.com/bugsearch/bug/CSCvw08378

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.