Cisco Security Advisory
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A vulnerability in the Locator/ID Separation Protocol (LISP) of Cisco IOS Software running on the Cisco Catalyst 6500 and 6800 Series Switches and Cisco NX-OS Software running on the Cisco Nexus 7000 and Nexus 7700 Series Switches with an M1 Series Gigabit Ethernet Module could allow an unauthenticated, remote attacker to cause a reload of the vulnerable device.
The vulnerability is due to a lack of proper input validation when a malformed LISP packet header is received. An attacker could exploit this vulnerability by sending a malformed LISP packet on UDP port 4341. An exploit could allow the attacker to cause a denial of service (DoS) condition.
Cisco has released software updates that address this vulnerability.
This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160323-lisp
This advisory is part of the March 23, 2016, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes six Cisco Security Advisories that describe six vulnerabilities. All the vulnerabilities have a Security Impact Rating of "High." For a complete list of advisories and links to them, see Cisco Event Response: Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.
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Vulnerable Products
Cisco Catalyst 6500 and 6800 Series Switches running Cisco IOS Software, and Cisco Nexus 7000 and Nexus 7700 Series Switches with an M1 Series Gigabit Ethernet Module running Cisco NX-OS Software are vulnerable when LISP is configured. LISP is not enabled by default on either platform.
For information about which Cisco IOS and NX-OS Software versions are vulnerable, see the "Fixed Software" section of this advisory.
Cisco Catalyst 6500 and 6800 Series Switches
LISP support was first introduced in release 15.1(1)SY1. To determine if LISP is configured on the device, use the show running-config | include lisp command to see if router lisp is configured, as shown in the following example:
iosRouter# show running-config | include lisp
Determining the Cisco IOS Software Release
router lisp
To determine which Cisco IOS Software release is running on a Cisco product, administrators can log in to the device and issue the show version command to display the system banner. If the device is running Cisco IOS Software, the system banner displays text similar to Cisco Internetwork Operating System Software or Cisco IOS Software. The image name displays in parentheses, followed by the Cisco IOS Software release number and release name.
The following example identifies a Cisco product that is running Cisco IOS Software Release 15.2(1)SY1 with an installed image name of c6880x-ADVENTERPRISEK9-M:
iosRouter# show version
Additional information about Cisco IOS Software release naming conventions is available in White Paper: Cisco IOS and NX-OS Software Reference Guide.
Cisco IOS Software, c6880x Software (c6880x-ADVENTERPRISEK9-M), Version 15.2(1)SY1, RELEASE SOFTWARE (fc5)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2015 by Cisco Systems, Inc.
Compiled Mon 11-May-15 00:26 by prod_rel_team
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Nexus 7000 and 7700 Series Switches
The Nexus 7000 and 7700 Series Switches added LISP support in software release 5.2(1). The Nexus 7000 and 7700 Series Switches with LISP configured are vulnerable only if the LISP packet is input on an M1 Series Gigabit Ethernet Module. Use the show module | include M1 command to check whether an M1 module is installed in the Nexus 7000 chassis, as shown in the following example:
nxosRouter# show module | include M1
If there is an M1 Series Gigabit Ethernet Module installed, it will be vulnerable only if LISP packets are input to interfaces configured on this module. To check whether the LISP feature is enabled, use the show feature | include lisp command, as in the following example:
3 48 10/100/1000 Mbps Ethernet XL Module N7K-M148GT-11L powered-up
nxosRouter# show feature | include lisp
The show ip lisp command can be used to determine the LISP configuration for the M1 interfaces:
lisp 1 enabled
nxosRouter# show ip lisp
For more information on the Nexus 7000 and 7700 Series Switches LISP Configuration, see Configuring Locator/ID Separation Protocol.
LISP IP Configuration Information for VRF "default" (iid 1)
Ingress Tunnel Router (ITR):enabled
Egress Tunnel Router (ETR):disabled
Proxy-ITR Router (PTR):disabled
Proxy-ETR Router (PETR):disabled
Map Resolver (MR):disabled
Map Server (MS):disabled
LISP Multicast:disabled
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Determine the Cisco NX-OS Software Release
To determine the Cisco NX-OS Software release that is running on a Cisco Nexus 7000 Series switch, administrators can log in to the device and issue the show version command. The following example identifies the 6.2(14) release:
nxosRouter# show version
Cisco Nexus Operating System (NX-OS) Software
TAC support: http://www.cisco.com/tac
Documents: http://www.cisco.com/en/US/products/ps9372/tsd_products_support_series_home.html
Copyright (c) 2002-2015, Cisco Systems, Inc. All rights reserved.
The copyrights to certain works contained in this software are
owned by other third parties and used and distributed under
license. Certain components of this software are licensed under
the GNU General Public License (GPL) version 2.0 or the GNU
Lesser General Public License (LGPL) Version 2.1. A copy of each
such license is available at
http://www.opensource.org/licenses/gpl-2.0.php and
http://www.opensource.org/licenses/lgpl-2.1.php
Software
BIOS: version 2.12.0
kickstart: version 6.2(14)
system: version 6.2(14).
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.Note: The following Cisco M1 Series Gigabit Ethernet Module Series modules are no longer supported as of Cisco NX-OS Release 7.3(0)D1(1):
- N7K-M148GT-11
- N7K-M132XP-12
- N7K-M148GS-11
For further information, see the Unsupported Hardware section in Cisco Nexus 7000 Series NX-OS Release Notes, Release 7.3.
Products Confirmed Not Vulnerable
No other Cisco products are currently known to be affected by this vulnerability.
Cisco has confirmed that this vulnerability does not affect Cisco IOS-XR and Cisco IOS-XE.
Cisco 7600 Series Routers are not affected by this vulnerability.
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The LISP network architecture and protocol implements a new semantic for IP addressing by creating two new namespaces: Endpoint Identifiers (EIDs), which are assigned to end hosts, and Routing Locators (RLOCs), which are assigned to devices (primarily routers) that make up the global routing system. Splitting EID and RLOC functions improves routing system scalability, multihoming efficiency, and ingress traffic engineering. LISP end site support is configured on devices such as Cisco routers. This vulnerability is present for any type of LISP configuration in which a LISP packet is input on an affected interface.
The Cisco Catalyst 6500 and 6800 Series Switches and the Cisco Nexus 7000 and 7700 Series Switches with an M1 Series Gigabit Ethernet Module share a common ASIC, which could crash when a malformed LISP packet is received. For this vulnerability to be exploited, the LISP packet must be destined to UDP port number 4341, which is the well-known port number for LISP, the UDP LISP header must be malformed, and the header length must be incorrect.
On the Cisco Catalyst 6500 and 6800 Series Switches this vulnerability results in a complete reload of the device. On the Cisco Nexus 7000 and 7700 Series Switches with M1 Series Gigabit Ethernet Module installed, the M1 module itself reloads but the rest of the chassis remains stable.
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On Cisco Catalyst 6500 and 6800 Series Switches, an exploit of this vulnerability causes the device to reload with a reset reason of EARL Recovery Patch errors.
On Cisco Nexus 7000 and 7700 Series Switches with M1 Series Gigabit Ethernet Module, this vulnerability causes the M1 module to reload with a reset reason of Fatal Interrupt Metropolis device error.
Cisco Technical Assistance Center (TAC) should review the system log file to determine if the device has been affected by this vulnerability.
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There are no workarounds that address this vulnerability.
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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:
http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.htmlAdditionally, 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 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.htmlCustomers 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.
Cisco IOS SoftwareTo help customers determine their exposure to vulnerabilities in Cisco IOS Software, Cisco provides a tool, the Cisco IOS Software Checker, that identifies any Cisco Security Advisories that impact a specific Cisco IOS Software release and the earliest release that fixes the vulnerabilities described in each advisory ("First Fixed"). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities described in all the advisories identified ("Combined First Fixed").
Customers can use this tool to perform the following tasks:
- Initiate a search by choosing one or more releases from a drop-down menu or uploading a file from a local system for the tool to parse
- Enter the output of the show version command for the tool to parse
- Create a custom search by including all previously published Cisco Security Advisories, a specific advisory, or all advisories in the most recent bundled publication
To determine whether a release is affected by any published Cisco Security Advisory, use the Cisco IOS Software Checker on Cisco.com or enter a Cisco IOS Software release—for example, 15.1(4)M2—in the following field:
Cisco NX-OS Software
This vulnerability is fixed in software version 7.3(0)D1(1). The Cisco Nexus 7000 and Nexus 7700 Series Software can be downloaded from the Software Center on Cisco.com by visiting http://www.cisco.com/cisco/software/navigator.html and choosing Downloads Home > Products > Switches > Data Center Switches > Nexus 7000 Series Switches.
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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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This vulnerability was found during resolution of a customer case handled by the Cisco TAC.
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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 2016-March-23
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