Cisco Security Advisory Cisco Nexus 9000 Series ACI Mode Switch ICMP Record Route Vulnerability High Advisory ID: cisco-sa-20160203-n9knci First Published: 2016 February 3 16:00 GMT Version 1.0: Final Workarounds: Yes Cisco Bug IDs: CSCuq57512 CVE-2015-6398 CWE-399 CVSS Score: Base 7.8, Temporal 6.4 Click Icon to Copy Verbose Score

AV:N/AC:L/Au:N/C:N/I:N/A:C/E:F/RL:OF/RC:C CVE-2015-6398 CWE-399 Download CVRF Download PDF Email Summary



The vulnerability is due to improper handling of an ICMP packet with the IPv4 Type 7 option for record route. An attacker could exploit this vulnerability by sending an ICMP packet with the record route option to an interface on the affected switch. An exploit could allow the attacker to cause a DoS condition because the switch will reload each time the ICMP packet is received.



Cisco has released software updates that address this vulnerability. A workaround that addresses this vulnerability is available.



This advisory is available at the following link: A vulnerability in the ICMP implementation in the Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch could allow an unauthenticated, remote attacker to cause the switch to reload, resulting in a denial of service (DoS) condition.The vulnerability is due to improper handling of an ICMP packet with the IPv4 Type 7 option for record route. An attacker could exploit this vulnerability by sending an ICMP packet with the record route option to an interface on the affected switch. An exploit could allow the attacker to cause a DoS condition because the switch will reload each time the ICMP packet is received.Cisco has released software updates that address this vulnerability. A workaround that addresses this vulnerability is available.This advisory is available at the following link: http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160203-n9knci Affected Products Vulnerable Products Cisco Nexus 9000 Series ACI Mode Switches running software versions prior to release 11.0(1c) are vulnerable. Products Confirmed Not Vulnerable No other Cisco products are currently known to be affected by this vulnerability. Cisco Nexus 9000 Series Switches and Cisco Application Policy Infrastructure Controller (APIC) are not affected. Indicators of Compromise This vulnerability will cause the affected device to reload and write a core file. Contact the Cisco Technical Assistance Center (TAC) to review the core file and confirm whether the device has been compromised by this vulnerability. Workarounds The workaround for this vulnerability is to drop all ICMP packets and should not be applied unless the device has been exploited by this vulnerability. This workaround can be applied only when working with the Cisco TAC.



To apply the workaround, the administrator must log in as the root user on the Cisco Nexus 9000 Series ACI Mode Switch. The command iptables -I INPUT 1 -p ICMP -j DROP will drop ICMP packets to the affected switch. The ICMP drop action can be removed with the command iptables -D INPUT 1. Fixed Software



http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html



Additionally, customers may only download software for which they have a valid license, procured from Cisco directly or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades.



When considering software upgrades, customers are advised to consult the Cisco Security Advisories and Responses archive at



In all cases, customers should ensure that the devices to upgrade 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.



Customers Without Service Contracts



Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco Technical Assistance Center (TAC):



http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html



Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.



Fixed Versions



The Cisco Nexus 9000 Series ACI Mode Switch ICMP Record Route Vulnerability is fixed in versions 11.0(1c) and later. The Cisco Nexus 9000 Series ACI Mode software can be downloaded from the Software Center on Cisco.com by visiting Downloads Home > Products > Switches > Data Center Switches > Nexus 9000 Series Switches. Cisco has released free software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license:Additionally, customers may only download software for which they have a valid license, procured from Cisco directly or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades.When considering software upgrades, customers are advised to consult the Cisco Security Advisories and Responses archive at http://www.cisco.com/go/psirt and review subsequent advisories to determine exposure and a complete upgrade solution.In all cases, customers should ensure that the devices to upgrade 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.Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco Technical Assistance Center (TAC):Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.Theis fixed in versions 11.0(1c) and later. The Cisco Nexus 9000 Series ACI Mode software can be downloaded from the Software Center on Cisco.com by visiting http://www.cisco.com/cisco/software/navigator.html and choosing Exploitation and Public Announcements 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. Source This vulnerability was found during investigation of a customer issue by the Cisco TAC. Cisco Security Vulnerability Policy 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. Subscribe Action Links for This Advisory ICMP Record Route vulnerability URL http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160203-n9knci Revision History Version Description Section Status Date 1.0 Initial public release. — Final 2016-February-03 Show Less Legal Disclaimer THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME. A standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products. Cisco Security Vulnerability Policy 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. Subscribe Action Links for This Advisory ICMP Record Route vulnerability