CVE-2020-3168: Cisco Nexus 1000V Switch for VMware vSphere Secure Login Enhancements Denial of Service Vulnerability
A vulnerability in the Secure Login Enhancements capability of Cisco Nexus 1000V Switch for VMware vSphere could allow an unauthenticated, remote attacker to cause an affected Nexus 1000V Virtual Supervisor Module (VSM) to become inaccessible to users through the CLI. The vulnerability is 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. An attacker could exploit this vulnerability by performing a high amount of login attempts against the affected device. A successful exploit could cause the affected device to become inaccessible to other users, resulting in a denial of service (DoS) condition requiring a manual power cycle of the VSM to recover.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Mitigate the denial of service by limiting high-rate or brute-force CLI login attempts against the affected Cisco Nexus 1000V Switch Secure Login Enhancements endpoint (e.g., use network controls/ACLs/WAF/rate-limiting to reduce login attempts from untrusted sources).
- Operational
If the device becomes inaccessible due to the DoS, perform a manual power cycle of the VSM to restore access.
Event History
Frequently Asked Questions
What is the vulnerability ID for this security issue?
The vulnerability ID for this security issue is CVE-2020-3168.
What is the affected software?
The affected software is Cisco Nx-os version 5.2(1)sv3(4.1a) and Cisco Nexus 1000v.
What is the severity of CVE-2020-3168?
The severity of CVE-2020-3168 is high with a severity value of 7.5.
How can an attacker exploit this vulnerability?
An unauthenticated, remote attacker can exploit this vulnerability to make the Nexus 1000V Virtual Supervisor Module (VSM) inaccessible to users through the CLI.
Is there a fix available for this vulnerability?
Please refer to the Cisco Security Advisory for information on available fixes.