Vulnerability identifier: #VU25654

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-3168

CWE-ID: CWE-399

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco Nexus 1000v Application Virtual Switch
Server applications / Virtualization software
Cisco NX-OS
Operating systems & Components / Operating system

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 resource allocation during failed CLI login attempts when login parameters that are part of the Secure Login Enhancements capability are configured on an affected device. A remote attacker can perform a high amount of login attempts against the affected device and cause it to become inaccessible to other users, resulting in a denial of service condition requiring a manual power cycle of the VSM to recover.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco Nexus 1000v Application Virtual Switch: All versions

Cisco NX-OS: 5.2.1 SV3.4.1a

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200226-nexus-1000v-dos

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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.