#VU46248 Inefficient Algorithmic Complexity in Cisco AsyncOS for Cisco Email Security Appliance - CVE-2020-3548

Vulnerability identifier: #VU46248

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-3548

CWE-ID: CWE-407

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 inefficient processing of incoming Transport Layer Security (TLS) traffic. A remote attacker can send specially crafted TLS packets, trigger a prolonged state of high CPU utilization and perform a denial of service (DoS) attack.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

Cisco AsyncOS for Cisco Email Security Appliance: 13.5.1 277

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External links
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-tls-dos-xW53TBhb

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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.