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Cisco Security Advisory

Cisco IOS Software Multicast Network Time Protocol Denial of Service Vulnerability

Advisory ID: cisco-sa-20130925-ntp

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130925-ntp

Revision 1.0

For Public Release 2013 September 25 16:00  UTC (GMT)

Related Resources:

View related Event ResponseView related Alert

Summary

A vulnerability in the implementation of the Network Time Protocol (NTP) feature in Cisco IOS Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition.

The vulnerability is due to the improper handling of multicast NTP packets that are sent to an affected device encapsulated in a Multicast Source Discovery Protocol (MSDP) Source-Active (SA) message from a configured MSDP peer. An attacker could exploit this vulnerability by sending multicast NTP packets to an affected device. Repeated exploitation could result in a sustained DoS condition.

Cisco has released free software updates that address this vulnerability. A workaround is available to mitigate this vulnerability.

This advisory is available at the following link: http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130925-ntp

Note: The September 25, 2013, Cisco IOS Software Security Advisory bundled publication includes eight Cisco Security Advisories. All advisories address vulnerabilities in Cisco IOS Software. Each Cisco IOS Software Security Advisory lists the Cisco IOS Software releases that correct the vulnerability or vulnerabilities detailed in the advisory as well as the Cisco IOS Software releases that correct all Cisco IOS Software vulnerabilities in the September 2013 bundled publication.

Individual publication links are in "Cisco Event Response: Semiannual Cisco IOS Software Security Advisory Bundled Publication" at the following link:

http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep13.html

Affected Products

Vulnerable Products

A Cisco device that is running an affected Cisco IOS Software release is vulnerable when the following two conditions are met:
  • The device configuration includes any multicast NTP configuration commands
  • The device has has at least one MSDP peer configured
The following steps can be used to determine whether the device meets the preceding conditions:

The show running-config | include ^interface|ntp multicast privileged EXEC command can be used to determine whether the device configuration includes any multicast NTP configuration commands. The following is the output from the show running-config | include ^interface|ntp multicast command executed on a device running Cisco IOS Software that has multiple interfaces configured for multicast NTP:
Router#show running-config | include ^interface|ntp multicast
interface Loopback0
interface Loopback1
interface FastEthernet0/0
 ntp multicast
interface FastEthernet0/1
interface FastEthernet0/2
interface FastEthernet0/3
interface FastEthernet1/0
 ntp multicast key 61560
interface FastEthernet1/1
interface FastEthernet1/2
 ntp multicast client
interface FastEthernet1/3
 ntp multicast client
 ntp multicast
Router#
Note: The next step can be skipped if the device does not have any multicast NTP commands in the configuration. The device is not vulnerable.

The show ip msdp summary privileged EXEC command can be used to determine whether the device has at least one MSDP peer configured. The following is the output from the show ip msdp summary command executed on a device running Cisco IOS Software that has one MSDP peer configured:
Router#show ip msdp summary 
MSDP Peer Status Summary
Peer Address     AS    State    Uptime/  Reset SA    Peer Name
                                Downtime Count Count
10.54.54.54      ?     Up       00:35:03 0     6     ?
Router#
A device without any MSDP peers configured is not vulnerable.

The processing of NTP multicast packets is not enabled by default.

To determine the Cisco IOS Software release that is running on a Cisco product, administrators can log in to the device and issue the show version command to display the system banner. The system banner confirms that the device is running Cisco IOS Software by displaying text similar to "Cisco Internetwork Operating System Software" or "Cisco IOS Software." The image name displays in parentheses, followed by "Version" and the Cisco IOS Software release name. Other Cisco devices do not have the show version command or may provide different output.

The following example identifies a Cisco product that is running Cisco IOS Software Release 15.0(1)M1 with an installed image name of C3900-UNIVERSALK9-M:

Router> show version 
Cisco IOS Software, C3900 Software (C3900-UNIVERSALK9-M), Version 15.0(1)M1, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2009 by Cisco Systems, Inc.
Compiled Wed 02-Dec-09 17:17 by prod_rel_team
!--- output truncated 

Additional information about Cisco IOS Software release naming conventions is available in "White Paper: Cisco IOS and NX-OS Software Reference Guide" at http://www.cisco.com/web/about/security/intelligence/ios-ref.html.


Products Confirmed Not Vulnerable

The following products are confirmed not to be affected by this vulnerability:
  • Cisco IOS XR Software. 
No other Cisco products are currently known to be affected by this vulnerability.

Details

NTP is designed to time-synchronize a network of machines. NTP runs on UDP, which is transported on IP. Networking devices running NTP can be configured to operate in a variety of association modes when synchronizing time with reference time sources. A networking device can obtain time information on a network in two ways: by polling host servers and by listening to NTP broadcasts.

A vulnerability in the implementation of the Network Time Protocol (NTP) feature in Cisco IOS Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition.

The vulnerability is due to the improper handling of multicast NTP packets that are sent to an affected device encapsulated in a Multicast Source Discovery Protocol (MSDP) Source-Active (SA) message from a configured MSDP peer. An attacker could exploit this vulnerability by sending multicast NTP packets to an affected device. Repeated exploitation could result in a sustained DoS condition.

This vulnerability has been documented in Cisco bug ID CSCuc81226 (registered customers only) and has been assigned the Common Vulnerabilities and Exposures (CVE) ID CVE-2013-5472

Vulnerability Scoring Details

Cisco has scored the vulnerability in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this security advisory is in accordance with CVSS version 2.0.

CVSS is a standards-based scoring method that conveys vulnerability severity and helps organizations determine the urgency and priority of a response.

Cisco has provided a base and temporal score. Customers can also compute environmental scores that help determine the impact of the vulnerability in their own networks.

Cisco has provided additional information regarding CVSS at the following link:

http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html

Cisco has also provided a CVSS calculator to compute the environmental impact for individual networks at the following link:

 

http://intellishield.cisco.com/security/alertmanager/cvss

CSCuc81226:Cisco IOS Software Multicast NTP Denial of Service Vulnerability

Calculate the environmental score of CSCuc81226

CVSS Base Score - 7.1

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Medium

None

None

None

Complete

CVSS Temporal Score - 5.9

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed


Impact

Successful exploitation of this vulnerability may cause the affected device to reload. Repeated exploitation could result in a sustained DoS condition.

Software Versions and Fixes

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


Cisco IOS Software

Each row of the following Cisco IOS Software table corresponds to a Cisco IOS Software train. If a particular train is vulnerable, the earliest releases that contain the fix are listed in the First Fixed Release column. The First Fixed Release for All Advisories in the September 2013 Bundled Publication column lists the earliest possible releases that correct all the published vulnerabilities in the Cisco IOS Software Security Advisory bundled publication. Cisco recommends upgrading to the latest available release where possible.

The Cisco IOS Software Checker allows customers to search for Cisco Security Advisories that address specific Cisco IOS Software releases. This tool is available on the Cisco Security (SIO) portal at http://tools.cisco.com/security/center/selectIOSVersion.x


Major Release      Availability of Repaired Releases
Affected 12.0-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Bundled Publication
12.0S Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.0SY Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.0SZ Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Affected 12.2-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Bundled Publication
12.2EX Note: Releases prior to 12.2(58)EX are vulnerable; Releases 12.2(58)EX and later are not vulnerable.
Vulnerable; First fixed in Release 15.0SE
12.2EY Note: Releases prior to 12.2(58)EY are vulnerable; Releases 12.2(58)EY and later are not vulnerable.
Vulnerable; First fixed in Release 15.2S
12.2EZ Note: Releases prior to 12.2(58)EZ are vulnerable; Releases 12.2(58)EZ and later are not vulnerable.
Releases prior to 12.2(60)EZ2 are vulnerable; Releases 12.2(60)EZ2 and later are not vulnerable. First fixed in Release 15.0SE
12.2IRB Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2IRC Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2IRD Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2IRE Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2IRF Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2IRG Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IRH Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IRI Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IXG Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IXH Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2MC Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.2MRA Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2MRB Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SB 12.2(33)SB15
12.2(33)SB15
12.2SCA Vulnerable; First fixed in Release 12.2SCH
Vulnerable; First fixed in Release 12.2SCH
12.2SCB Vulnerable; First fixed in Release 12.2SCH
Vulnerable; First fixed in Release 12.2SCH
12.2SCC Vulnerable; First fixed in Release 12.2SCH
Vulnerable; First fixed in Release 12.2SCH
12.2SCD Vulnerable; First fixed in Release 12.2SCH
Vulnerable; First fixed in Release 12.2SCH
12.2SCE Vulnerable; First fixed in Release 12.2SCH
Vulnerable; First fixed in Release 12.2SCH
12.2SCF Vulnerable; First fixed in Release 12.2SCH
Vulnerable; First fixed in Release 12.2SCH
12.2SCG Vulnerable; First fixed in Release 12.2SCH
Vulnerable; First fixed in Release 12.2SCH
12.2SCH 12.2(33)SCH1
12.2(33)SCH1
12.2SE 12.2(55)SE8
12.2(58)SE

12.2(55)SE8
12.2SEG Vulnerable; migrate to any release in 15.0SE
Vulnerable; First fixed in Release 15.0SE
12.2SG
12.2(53)SG10; available December 2013 *

12.2(53)SG10; available December 2013 *
12.2SGA Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SM Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SQ Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SRA Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2SRB Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2SRC Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2SRD Vulnerable; First fixed in Release 12.2SRE
Vulnerable; First fixed in Release 12.2SRE
12.2SRE 12.2(33)SRE9
12.2(33)SRE9
12.2STE Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SV Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SVD Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SVE Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SW Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.2SXF Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SXH Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SXI 12.2(33)SXI12
12.2(33)SXI12
12.2SXJ Not vulnerable
12.2(33)SXJ6
12.2SY Vulnerable; First fixed in Release 15.0SY
Vulnerable; First fixed in Release 15.0SY
12.2WO Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2XNA Please see Cisco IOS XE Software Availability
Please see Cisco IOS XE Software Availability
12.2XNB Please see Cisco IOS XE Software Availability
Please see Cisco IOS XE Software Availability
12.2XNC Please see Cisco IOS XE Software Availability
Please see Cisco IOS XE Software Availability
12.2XND Please see Cisco IOS XE Software Availability
Please see Cisco IOS XE Software Availability
12.2XNE Please see Cisco IOS XE Software Availability
Please see Cisco IOS XE Software Availability
12.2XNF Please see Cisco IOS XE Software Availability
Please see Cisco IOS XE Software Availability
12.2XO Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZYA Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Affected 12.3-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Bundled Publication
12.3BC Vulnerable; First fixed in Release 12.2SCH
Vulnerable; First fixed in Release 12.2SCH
12.3JEC Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.3JED Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.3JEE Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.3JX Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.3XI Vulnerable; First fixed in Release 12.2SB
Vulnerable; First fixed in Release 12.2SB
12.3XJ Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3XK Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3XL Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3XQ Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3XR Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3XU Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3XW Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3XX Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YD Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YF Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YG Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YI Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YJ Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YK Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YM Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YQ Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YS Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YT Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YU Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YX Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.3YZ Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.3ZA Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
Affected 12.4-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Bundled Publication
12.4 Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4GC Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4JA Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4JAL Not vulnerable
Vulnerable; First fixed in Release 12.4JAM
12.4JAM Not vulnerable
12.4(25e)JAM2
12.4JAN Not vulnerable
Not vulnerable
12.4JAX Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4JAZ Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4JDA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4JDC Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4JDD Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4JDE Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4JHA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4JHB Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4JHC Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4JK Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4JL Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4JX Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4JY Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4JZ Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4MD Note: Releases prior to 12.4(22)MD are vulnerable; Releases 12.4(22)MD and later are not vulnerable.
Vulnerable; First fixed in Release 12.4MDB
12.4MDA Not vulnerable
Vulnerable; First fixed in Release 12.4MDB
12.4MDB Not vulnerable
12.4(24)MDB15
12.4MR Note: Releases prior to 12.4(20)MR are vulnerable; Releases 12.4(20)MR and later are not vulnerable.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4MRA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4MRB Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4SW Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4T Note: Releases prior to 12.4(20)T are vulnerable; Releases 12.4(20)T and later are not vulnerable.
Vulnerable; First fixed in Release 15.1M
12.4XA Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XB Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XC Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XD Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XE Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XF Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XG Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XJ Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XK Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XL Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4XM Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XN Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4XP Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4XQ Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XR Note: Releases prior to 12.4(22)XR are vulnerable; Releases 12.4(22)XR and later are not vulnerable.
Vulnerable; First fixed in Release 15.1M
12.4XT Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XV Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4XW Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XY Vulnerable; migrate to any release in 15.0M
Vulnerable; First fixed in Release 15.1M
12.4XZ Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4YA Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4YB Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4YD Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.4YE Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.4YG Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Affected 15.0-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Bundled Publication
15.0EA Not vulnerable
15.0(2)EA1
15.0EB Not vulnerable
Vulnerable; migrate to any release in 15.2E
15.0EC Not vulnerable
Vulnerable; migrate to any release in 15.2E
15.0ED Not vulnerable
Note: Releases prior to 15.0(2)ED1 are vulnerable; Releases 15.0(2)ED1 and later are not vulnerable.
15.0EH Not vulnerable
Not vulnerable
15.0EJ Not vulnerable
Not vulnerable
15.0EX Cisco IOS XE devices: Please see Cisco IOS XE Software Availability

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0EY Not vulnerable
15.0(2)EY2
15.0EZ Not vulnerable

Only Release 15.0(2)EZ is vulnerable
15.0M Not vulnerable
Vulnerable; First fixed in Release 15.1M
15.0MR Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.0S Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
Vulnerable; First fixed in Release 15.1S
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0SE Not vulnerable
15.0(2)SE4
15.0SG Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0SQA Cisco IOS XE devices: Please see Cisco IOS XE Software Availability

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0SQB Cisco IOS XE devices: Please see Cisco IOS XE Software Availability

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0SY 15.0(1)SY3
15.0(1)SY5
15.0XA Not vulnerable
Vulnerable; First fixed in Release 15.1M
15.0XO Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
Affected 15.1-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Bundled Publication
15.1EY Not vulnerable
Vulnerable; First fixed in Release 15.2S
15.1GC Not vulnerable
Vulnerable; First fixed in Release 15.1M
15.1M Not vulnerable
15.1(4)M7
15.1MR Releases prior to 15.1(3)MR are vulnerable; Releases 15.1(3)MR and later are not vulnerable.
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.1MRA Not vulnerable
15.1(3)MRA2
15.1S Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.1(3)S6
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.1SG Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.1(2)SG1
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.1SNG Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.1SNH Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.1SNI Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.1SVD Not vulnerable
Not vulnerable
15.1SVE Not vulnerable
Not vulnerable
15.1SVF Not vulnerable
Not vulnerable
15.1SY Not vulnerable

15.1(1)SY2; Available on 28-OCT-13
15.1(2)SY
15.1T Not vulnerable
Vulnerable; First fixed in Release 15.1M
15.1XO Not vulnerable
Not vulnerable
Affected 15.2-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Bundled Publication
There are no affected 15.2 based releases
Affected 15.3-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Bundled Publication
There are no affected 15.3 based releases

* Cisco Catalyst 4500 Series Switches with Cisco Catalyst 4500 Supervisor Engines 6-E or 6L-E can migrate to Cisco IOS Software Release 15.1SG.

 

Cisco IOS XE Software

Cisco IOS XE Software is affected by the vulnerability that is disclosed in this document.

Cisco IOS XE Software Release First Fixed Release First Fixed Release for All Advisories in the September 2013 Cisco IOS Software Security Advisory Bundled Publication
2.1.x Vulnerable; migrate to 3.3.0S or later. Vulnerable; migrate to 3.4.6S or later.
2.2.x Vulnerable; migrate to 3.3.0S or later. Vulnerable; migrate to 3.4.6S or later.
2.3.x Vulnerable; migrate to 3.3.0S or later. Vulnerable; migrate to 3.4.6S or later.
2.4.x Vulnerable; migrate to 3.3.0S or later. Vulnerable; migrate to 3.4.6S or later.
2.5.x Vulnerable; migrate to 3.3.0S or later. Vulnerable; migrate to 3.4.6S or later.
2.6.x Vulnerable; migrate to 3.3.0S or later. Vulnerable; migrate to 3.4.6S or later.
3.1.xS Vulnerable; migrate to 3.3.0S or later. Vulnerable; migrate to 3.4.6S or later.
3.1.xSG Vulnerable; migrate to 3.3.0SG or later. Vulnerable; migrate to 3.4.1SG or later.
3.2.xS Vulnerable; migrate to 3.3.0S or later. Vulnerable; migrate to 3.4.6S or later.
3.2.xSE Not vulnerable 3.2.3SE
3.2.xSG Vulnerable; migrate to 3.3.0SG or later. Vulnerable; migrate to 3.4.1SG or later.
3.2.xXO Vulnerable; migrate to 3.3.0XO or later. Vulnerable; migrate to 3.3.0XO or later.
3.2.xSQ Vulnerable; migrate to 3.3.0SQ or later. Vulnerable; migrate to 3.3.0SQ or later.
3.3.xS 3.3.0S Vulnerable; migrate to 3.4.6S or later.
3.3xSG Not vulnerable Vulnerable; migrate to 3.4.1SG or later.
3.3.xXO Not vulnerable Not vulnerable
3.3.xSQ Not vulnerable Not vulnerable
3.4.xS Not vulnerable 3.4.6S
3.4.xSG Not vulnerable 3.4.1SG *
3.5.xS Not vulnerable Vulnerable; migrate to 3.7.4S or later.
3.5.xE Not vulnerable Not vulnerable
3.6.xS Not vulnerable Vulnerable; migrate to 3.7.4S or later.
3.7.xS Not vulnerable 3.7.4S
3.8.xS Not vulnerable Vulnerable; migrate to 3.9.2S or later.
3.9.xS Not vulnerable 3.9.2S
3.10.xS Not vulnerable Not vulnerable

* Cisco Catalyst 4500 Series Switches with Cisco Catalyst 4500 Supervisor Engines 7-E and 7L-E and Cisco Catalyst 4500-X Series Switches can migrate to Cisco IOS XE Software Release 3.4SG.

For a mapping of Cisco IOS XE Software releases to Cisco IOS Software releases, refer to Cisco IOS XE 2 Release Notes, Cisco IOS XE 3S Release Notes, and Cisco IOS XE 3SG Release Notes.

Cisco IOS XR Software

Cisco IOS XR Software is not affected by the vulnerability that is disclosed in this document



Workarounds

Customers who do not require multicast NTP traffic from other multicast domains can configure an MSDP SA filter to drop the traffic coming from an MSDP peer and sent to the NTP multicast group. The following example shows an MSDP SA filter that will be applied to all MSDP traffic sent to the device from a configured MSDP peer with address 10.54.54.54
access-list 111 remark -- Deny traffic from any source to the NTP multicast group
access-list 111 deny ip any host 224.0.1.1
access-list 111 remark -- Allow everything else
access-list 111 permit ip any any
ip msdp sa-filter in 10.54.54.54 list 111
Note: the previous MSDP SA filter will need to be applied to each and every MSDP peer configured on the device, and should be customized according to the specific environment.

Refer to http://www.cisco.com/en/US/tech/tk828/technologies_tech_note09186a0080093fda.shtml for additional information on MSDP SA filtering recommendations.

Obtaining Fixed Software

Cisco has released free software updates that address the vulnerability described in this advisory. Prior to deploying software, customers are advised to consult their maintenance providers or check the software for feature set compatibility and known issues that are specific to their environments.

Customers may only install and expect support for feature sets they have purchased. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license at http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html.

Customers with Service Contracts

Customers with contracts should obtain upgraded software through their regular update channels. For most customers, upgrades should be obtained through the Software Navigator on Cisco.com at http://www.cisco.com/cisco/software/navigator.html.

Customers Using Third-Party Support Organizations

Customers with Cisco products that are provided or maintained through prior or existing agreements with third-party support organizations, such as Cisco Partners, authorized resellers, or service providers, should contact that organization for assistance with the appropriate course of action.

The effectiveness of any workaround or fix depends on specific customer situations, such as product mix, network topology, traffic behavior, and organizational mission. Because of the variety of affected products and releases, customers should consult their service providers or support organizations to ensure that any applied workaround or fix is the most appropriate in the intended network before it is deployed.

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):

  • +1 800 553 2447 (toll free from within North America)
  • +1 408 526 7209 (toll call from anywhere in the world)
  • e-mail: tac@cisco.com

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. Customers without service contracts should request free upgrades through the TAC.

Refer to Cisco Worldwide Contacts at http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html for additional TAC contact information, including localized telephone numbers, instructions, and e-mail addresses for support in various languages.

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.

This vulnerability was found when troubleshooting a customer case.

Status of This Notice: Final

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 stand-alone copy or Paraphrase of the text of this document that omits the distribution URL in the following section is an uncontrolled copy, and may lack important information or contain factual errors.


Distribution

This advisory is posted on Cisco Security at the following link:

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130925-ntp

Additionally, a text version of this advisory is clear signed with the Cisco PSIRT PGP key and circulated among the following e-mail addresses:

  • cust-security-announce@cisco.com
  • first-bulletins@lists.first.org
  • bugtraq@securityfocus.com
  • vulnwatch@vulnwatch.org
  • cisco@spot.colorado.edu
  • cisco-nsp@puck.nether.net
  • full-disclosure@lists.grok.org.uk

Future updates of this advisory, if any, will reside on Cisco.com but may not be announced on mailing lists. Users can monitor this advisory's URL for any updates.


Revision History

Revision 1.0 2013-September-25 Initial public release

Cisco Security Procedures

Complete information about reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco is available on Cisco.com at http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html. This web page includes instructions for press inquiries regarding Cisco Security Advisories. All Cisco Security Advisories are available at http://www.cisco.com/go/psirt.
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