#VU68968 Resource exhaustion in Cisco AsyncOS for Cisco Email Security Appliance - CVE-2022-20960

Vulnerability identifier: #VU68968

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2022-20960

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

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

Vendor: Cisco Systems, Inc

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper handling of certain TLS connections processed by the device. A remote attacker can cause the device to drop new TLS email messages that come from the associated email servers.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco AsyncOS for Cisco Email Security Appliance: before 14.2.1-015

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External links
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-dos-gdghHmbV
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwc35162

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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 Internet.

Is there known malware, which exploits this vulnerability?

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