AV:N/AC:L/Au:N/C:N/I:N/A:C/E:F/RL:OF/RC:C
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A vulnerability in the Internet Key Exchange (IKE) protocol of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a memory leak that could lead to a device reload.
The vulnerability is due to incorrect handling of malformed IKE packets by the affected software. An attacker could exploit this vulnerability by sending crafted IKE packets to a device configured with features that leverage IKE version 1 (IKEv1).
Although IKEv1 is automatically enabled on a Cisco IOS Software and Cisco IOS XE Software when IKEv1 or IKE version 2 (IKEv2) is configured, the vulnerability can be triggered only by sending a malformed IKEv1 packet.
In specific conditions, normal IKEv1 packets can also cause an affected release of Cisco IOS Software to leak memory.
Only IKEv1 is affected by this vulnerability.
An exploit could cause Cisco IOS Software not to release allocated memory, causing a memory leak. A sustained attack may result in a device reload.
Cisco has released software updates that address this vulnerability. There are no workarounds to mitigate this vulnerability.
This advisory is available at the following link:
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130925-ike
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
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Vulnerable Products
Although only IKEv1 packets can be used to trigger this vulnerability, devices that are running Cisco IOS Software or Cisco IOS XE Software are vulnerable when they are configured to use IKEv1 or IKEv2.
Configuring IKEv2 on Cisco IOS Software or Cisco IOS XE Software automatically enables IKEv1.
A number of features use IKEv1, including different types of VPNs such as the following:
- LAN-to-LAN VPN
- Remote access VPN (excluding SSLVPN)
- Dynamic Multipoint VPN (DMVPN)
- Group Domain of Interpretation (GDOI)
The preferred method to determine whether a device has been configured for IKE is to issue the show ip sockets or show udp EXEC command. If the device has UDP port 500, UDP port 4500, or UDP port 848 open, it is processing IKE packets.
In the following example, the device is processing IKE packets in UDP port 500 and UDP port 4500, using either IP version 4 (IPv4) or IP version 6 (IPv6):
router# show udp
Proto Remote Port Local Port In Out Stat TTY OutputIF
17 --listen-- 192.168.130.21 500 0 0 1001011 0
17(v6) --listen-- UNKNOWN 500 0 0 1020011 0
17 --listen-- 192.168.130.21 4500 0 0 1001011 0
17(v6) --listen-- UNKNOWN 4500 0 0 1020011 0
!--- Output truncated
router#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
Cisco IOS XR Software is not affected by this vulnerability.
Cisco ASA 5500 Series Adaptive Security Appliance is not affected by this vulnerability.
No other Cisco products are currently known to be affected by this vulnerability.
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The IKE protocol is used in the IP Security (IPsec) protocol suite to negotiate cryptographic attributes that will be used to encrypt or authenticate the communication session. These attributes include cryptographic algorithm, mode, and shared keys. The result of IKE is a shared session secret that will be used to derive cryptographic keys.
Cisco IOS Software or Cisco IOS XE Software support IKE for IPv4 and IPv6 communications. IKE communication can use any of the following UDP ports:
- UDP port 500
- UDP port 4500, Network Address Translation (NAT) Traversal (NAT-T)
- UDP port 848, Group Domain of Interpretation (GDOI)
A vulnerability in the Internet Key Exchange (IKE) protocol of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a memory leak that could lead to a device reload.
The vulnerability is due to incorrect handling of malformed IKE packets by the affected software. An attacker could exploit this vulnerability by sending crafted IKE packets to a device configured with features that leverage IKE version 1 (IKEv1).
Although IKEv1 is automatically enabled on a Cisco IOS Software and Cisco IOS XE Software when IKEv1 or IKE version 2 (IKEv2) is configured, the vulnerability can be triggered only by sending a malformed IKEv1 packet.
In specific conditions, normal IKEv1 packets can also cause an affected release of Cisco IOS Software to leak memory.
Only IKEv1 is affected by this vulnerability.
An exploit could cause Cisco IOS Software not to release allocated memory, causing a memory leak. A sustained attack may result in a device reload.
An attacker could exploit this vulnerability using either IPv4 or IPv6 on any of the listed UDP ports.
How to Determine Whether the Vulnerability Has Been Exploited
To determine whether the vulnerability has been exploited on an affected device, issue the show memory debug leaks summary command from the command-line interface.
The following example shows the output of an affected Cisco IOS or Cisco IOS XE device where there are observed memory leaks in IKE FSM CONTEXT:
Router#show memory debug leaks summary
Adding blocks for GD...
I/O memory
Alloc PC Size Blocks Bytes What
Processor memory
Alloc PC Size Blocks Bytes What
0x651A3D38 0000000092 0000000005 0000000460 IKE FSM CONTEXT
0x651A3D38 0000000104 0000000002 0000000208 IKE FSM CONTEXT
0x651A3D38 0000000112 0000000002 0000000224 IKE FSM CONTEXT
0x651A3D38 0000000156 0000000002 0000000312 IKE FSM CONTEXT
Note: The show memory debug leaks summary command may be CPU intensive and should be used with caution.
This vulnerability is documented in Cisco bug ID CSCtx66011 (registered customers only) and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2013-5473.
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There are no workarounds for this vulnerability.
The following identification mechanism exists for this vulnerability.
Embedded Event Manager (EEM)
A Cisco IOS Embedded Event Manager (EEM) policy that is based on Tool Command Language (Tcl) can be used on vulnerable Cisco IOS devices to identify and detect a memory leak that is caused by this vulnerability. The policy allows administrators to monitor the memory for the affected process on a Cisco IOS device. When Cisco IOS EEM detects potential exploitation of this vulnerability, the policy can trigger a response by sending an alert to the network administrator, who could then decide to implement an upgrade or reload the device to recover the lost memory at a suitable time. The example policy is based on a Tcl script that sends a syslog message when the memory keeps dropping and reaches EEM_IKE_BUFF_INCR_THRES and when the IKE buffers have dropped EEM_IKE_BUFF_INCR_THRES times. If IKE buffers are freed the counter starts counting from zero. After generating the memory leak syslog message the script re-initializes.
The Tcl script is available for download in Cisco Beyond: Embedded Event Manager (EEM) Scripting Community.
A sample device configuration follows:
event manager environment EEM_MEM_LEAK_INTERVAL 20
event manager environment EEM_MEM_LEAK_MAX_RUNTIME 5
event manager environment EEM_IKE_BUFF_INCR_THRES 3
event manager environment EEM_FREE_MEMORY_THRES 70
event manager directory user policy "flash:/"
event manager policy eem_ike_mem_leak.tcl
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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 Cisco IOS Software Security Advisory Bundled Publication There are no affected 12.0 based releases Affected 12.2-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Cisco IOS Software Security Advisory Bundled Publication 12.2EX Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2EY Not vulnerable
Vulnerable; First fixed in Release 15.2S
12.2EZ 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 Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2IRC Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2IRD Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2IRE Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2IRF Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2IRG Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IRH Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IRI Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IXG Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IXH Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2MC Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.2MRA Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2MRB Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SB Not vulnerable
12.2(33)SB15
12.2SCA Not vulnerable
Vulnerable; First fixed in Release 12.2SCH
12.2SCB Not vulnerable
Vulnerable; First fixed in Release 12.2SCH
12.2SCC Not vulnerable
Vulnerable; First fixed in Release 12.2SCH
12.2SCD Not vulnerable
Vulnerable; First fixed in Release 12.2SCH
12.2SCE Not vulnerable
Vulnerable; First fixed in Release 12.2SCH
12.2SCF Not vulnerable
Vulnerable; First fixed in Release 12.2SCH
12.2SCG Not vulnerable
Vulnerable; First fixed in Release 12.2SCH
12.2SCH Not vulnerable
12.2(33)SCH1
12.2SE Not vulnerable
12.2(55)SE8
12.2SEG Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2SG Not vulnerable
12.2(53)SG10; available December 2013 *
12.2SGA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SM Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SQ Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SRA Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2SRB Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2SRC Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2SRD Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2SRE Not vulnerable
12.2(33)SRE9
12.2STE Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SV Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SVD Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SVE Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SW Not vulnerable
Vulnerable; First fixed in Release 15.1M
12.2SXF Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SXH Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SXI Not vulnerable
12.2(33)SXI12
12.2SXJ Not vulnerable
12.2(33)SXJ6
12.2SY Not vulnerable
Vulnerable; First fixed in Release 15.0SY
12.2WO Not vulnerable
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 Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZYA Not vulnerable
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 Cisco IOS Software Security Advisory Bundled Publication There are no affected 12.3 based releases Affected 12.4-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Cisco IOS Software Security Advisory Bundled Publication There are no affected 12.4 based releases Affected 15.0-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Cisco IOS Software Security Advisory Bundled Publication There are no affected 15.0 based releases Affected 15.1-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Cisco IOS Software Security Advisory 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 15.1(4)M5
15.1(4)M7
15.1MR Releases up to and including 15.1(1)MR4 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 Availability15.1SG 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 Availability15.1SNG 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)SY15.1T 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 Cisco IOS Software Security Advisory Bundled Publication 15.2E Not vulnerable
Not vulnerable
15.2GC 15.2(3)GC1
15.2(4)GC
Vulnerable; migrate to any release in 15.4T
15.2JA Not vulnerable
15.2(4)JA1
15.2JAX Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.2JB Not vulnerable
15.2(2)JB2
15.2JN Not vulnerable
Not vulnerable
15.2M Not vulnerable
15.2(4)M4
15.2S 15.2(4)S
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.2(4)S4
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability15.2SA Not vulnerable
15.2(2)SA
15.2SNG Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.2SNH Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.2SNI Not vulnerable
Vulnerable; First fixed in Release 15.3S
15.2T 15.2(3)T3
15.2(3)T4
Affected 15.3-Based Releases First Fixed Release First Fixed Release for All Advisories in the September 2013 Cisco IOS Software Security Advisory 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
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 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 Not vulnerable Vulnerable; migrate to 3.4.6S or later. 2.2.x Not vulnerable Vulnerable; migrate to 3.4.6S or later. 2.3.x Not vulnerable Vulnerable; migrate to 3.4.6S or later. 2.4.x Not vulnerable Vulnerable; migrate to 3.4.6S or later. 2.5.x Not vulnerable Vulnerable; migrate to 3.4.6S or later. 2.6.x Not vulnerable Vulnerable; migrate to 3.4.6S or later. 3.1.xS Not vulnerable Vulnerable; migrate to 3.4.6S or later. 3.1.xSG Not vulnerable Vulnerable; migrate to 3.4.1SG or later. 3.2.xS Not vulnerable Vulnerable; migrate to 3.4.6S or later. 3.2xSE Not vulnerable 3.2.3SE 3.2.xSG Not vulnerable Vulnerable; migrate to 3.4.1SG or later. 3.2.xXO Not vulnerable Vulnerable; migrate to 3.3.0XO or later. 3.2.xSQ Not vulnerable Vulnerable; migrate to 3.3.0SQ or later. 3.3.xS Not vulnerable Vulnerable; migrate to 3.4.6S or later. 3.3xSG Not vulnerable Vulnerable; migrate to 3.4.1SG or later. 3.3xXO Not vulnerable Not vulnerable 3.3xSQ Not vulnerable Not vulnerable 3.4.xS Only releases 3.4.2S through 3.4.5S are vulnerable. 3.4.6S 3.4.xSG Not vulnerable 3.4.1SG* 3.5.xE Not vulnerable Not vulnerable 3.5.xS Not vulnerable Vulnerable; migrate to 3.7.4S or later. 3.6.xS 3.6.1S 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.
Cisco IOS XR Software
Cisco IOS XR Software is not affected by any of the vulnerabilities that are disclosed in the September 2013 Cisco IOS Software Security Advisory Bundled Publication.
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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.
This vulnerability was discovered during resolution of a support case.
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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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Revision 1.0 2013-September-25 Initial public release
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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.
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