Cisco Nexus 9000 Series Switches Telnet Login Denial of Service Vulnerability

A vulnerability in the Telnet remote login functionality of Cisco NX-OS Software running on Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to cause a Telnet process used for login to terminate unexpectedly and the login attempt to fail. There is no impact to user traffic flowing through the device.

The vulnerability is due to incomplete input validation of Telnet packet headers. An attacker could exploit this vulnerability by sending a crafted Telnet packet to an affected system during a remote Telnet login attempt. A successful exploit could allow the attacker to cause the Telnet process on the affected system to restart unexpectedly, resulting in a denial of service (DoS) condition for the Telnet process.

There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-nss [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-nss”]