Cisco Security Advisory
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CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:X/RC:X
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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
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Vulnerable Products
This vulnerability affects Cisco Nexus 9000 Series Switches that are running Cisco NX-OS Software and are configured to allow remote Telnet connections to the device. For information about affected software releases, consult the Cisco bug ID(s) at the top of this advisory.Products Confirmed Not Vulnerable
No other Cisco products are currently known to be affected by this vulnerability.
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There are no workarounds that address this vulnerability.
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For information about fixed software releases, consult the Cisco bug ID(s) at the top of this advisory.
When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page, to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
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The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
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To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
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Show LessVersion Description Section Status Date 1.0 Initial public release. — Final 2017-March-15
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