Cisco Security Advisory

Cisco IOS Software Smart Install Denial of Service Vulnerability

Advisory ID: cisco-sa-20120328-smartinstall

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120328-smartinstall

Revision 1.1

Last Updated  2012 April 6 17:01  UTC (GMT)

For Public Release 2012 March 28 16:00  UTC (GMT)


Summary

Cisco IOS Software contains a vulnerability in the Smart Install feature that could allow an unauthenticated, remote attacker to cause a reload of an affected device if the Smart Install feature is enabled. The vulnerability is triggered when an affected device processes a malformed Smart Install message on TCP port 4786.

Cisco has released free software updates that address this vulnerability. A workaround may be available in some versions of Cisco IOS Software if the Smart Install feature is not needed.

This advisory is available at the following link:

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120328-smartinstall

Note: The March 28, 2012, Cisco IOS Software Security Advisory bundled publication includes nine Cisco Security Advisories. Each 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 vulnerabilities in the March 2012 bundled publication.

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

http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_mar12.html

Affected Products


Vulnerable Products

Devices configured as a Smart Install client or director are affected by this vulnerability. To display Smart Install information, use the show vstack config privileged EXEC command on the Smart Install director or client. The outputs of show commands are different when entered on the director or on the client. The following is the output of show vstack config in a Cisco Catalyst Switch configured as a Smart Install client:
switch#show vstack config
Role: Client
Vstack Director IP address: 10.1.1.163

The following is the output of show vstack config in a Cisco Catalyst Switch configured as a Smart Install director:

Director# show vstack config

Role: Director
Vstack Director IP address: 10.1.1.163
Vstack Mode: Basic
Vstack default management vlan: 1
Vstack management Vlans: none
Vstack Config file: tftp://10.1.1.100/default-config.txt
Vstack Image file: tftp://10.1.1.100/c3750e-universalk9-tar.122-
Join Window Details:
Window: Open (default)
Operation Mode: auto (default)
Vstack Backup Details:
Mode: On (default)
Repository: flash:/vstack (default)

A device that has the Smart Install feature enabled, either as a director or as a client, has TCP port 4786 in the open state. The command show tcp brief all | include 4786 can be used to determine if TCP port 4786 is open (and therefore, to determine if Smart Install is enabled). The following example shows the output from show tcp brief all | include 4786 on a device that has the Smart Install feature enabled:

router# show tcp brief all | include 4786
47DFD528  0.0.0.0.4786                *.*                         LISTEN

The Smart Install feature is enabled by default on devices that can be configured to act as Smart Install directors or Smart Install clients. These devices are LAN switches (Cisco Catalyst Switches), and the default configuration is to enable Smart Install with a client role.

The Smart Install feature is disabled by default on devices that can act only as Smart Install directors. These devices are typically routers and the feature is disabled by default because it requires additional configuration that is not necessary in the case of Smart Install clients.

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 IOS XE Software is not affected by this vulnerability.

No other Cisco products are currently known to be affected by this vulnerability.

Details

Smart Install is a plug-and-play configuration and image-management feature that provides zero-touch deployment for new LAN Ethernet switches. This feature allows, for example, new LAN switches to be deployed at new locations without any configuration.

A vulnerability exists in the Smart Install feature of Cisco IOS Software that could allow an unauthenticated, remote attacker to cause a reload of an affected device. Smart Install uses a Cisco proprietary protocol that runs over TCP port 4786. To exploit this vulnerability, an attacker needs to establish a TCP session on port 4786 of an affected device that has the Smart Install feature enabled, and then send a malformed Smart Install message.

This vulnerability is documented in Cisco bug ID CSCtt16051 (registered customers only), and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2012-0385.

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



CSCtt16051

Calculate the environmental score of CSCtt16051

CVSS Base Score - 7.8

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

None

None

None

Complete

CVSS Temporal Score - 6.4

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed

Impact

Successful exploitation of the vulnerability that is described in this advisory may cause a reload of an affected device. Repeated exploitation could result in a sustained denial of service condition.

Software Versions and Fixes

When considering software upgrades, also consult http://www.cisco.com/go/psirt and any subsequent advisories to determine exposure and a complete upgrade solution.

In all cases, customers should exercise caution to be certain the devices to be upgraded contain sufficient memory and that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, contact the Cisco Technical Assistance Center (TAC) or your contracted maintenance provider for assistance.

 

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 March 2012 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 Intelligence Operations (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 March 2012 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 March 2012 Cisco IOS Software Security Advisory Bundled Publication
12.2 Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2B Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2BC Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2BW Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2BX Not vulnerable
Vulnerable; First fixed in Release 12.2SB
12.2BY Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2BZ Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2CX Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2CY Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2CZ Not vulnerable
Vulnerable; First fixed in Release 12.0S
12.2DA Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2DD Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2DX Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2EU Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2EW Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2EWA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2EX Vulnerable; First fixed in Release 15.0SE
Releases up to and including 12.2(46)EX are not vulnerable.
Vulnerable; First fixed in Release 15.0SE
12.2EY Vulnerable; migrate to any release in 15.1EY
Releases up to and including 12.2(52)EY4 are not vulnerable.
12.2(52)EY4
12.2EZ Vulnerable; First fixed in Release 15.0SE
Releases up to and including 12.2(53)EZ are not vulnerable.
Vulnerable; First fixed in Release 15.0SE
12.2FX Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2FY Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2FZ Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2IRA Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
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.
12.2IXA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IXB Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IXC Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IXD Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IXE Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2IXF 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.
12.2JA Not vulnerable
Not vulnerable
12.2JK Not vulnerable
Not vulnerable
12.2MB Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2MC Not vulnerable
Vulnerable; First fixed in Release 15.0M
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.
12.2S Not vulnerable
Releases prior to 12.2(30)S are vulnerable; Releases 12.2(30)S and later are not vulnerable. First fixed in Release 12.0S
12.2SB Not vulnerable
12.2(33)SB12
12.2SBC Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2SCA Not vulnerable
Vulnerable; First fixed in Release 12.2SCE
12.2SCB Not vulnerable
Vulnerable; First fixed in Release 12.2SCE
12.2SCC Not vulnerable
Vulnerable; First fixed in Release 12.2SCE
12.2SCD Not vulnerable
Vulnerable; First fixed in Release 12.2SCE
12.2SCE Not vulnerable
12.2(33)SCE6
12.2SCF Not vulnerable
12.2(33)SCF2
12.2SE 12.2(55)SE5

12.2(55)SE5 *
12.2SEA Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2SEB Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2SEC Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2SED Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2SEE Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2SEF Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2SEG Not vulnerable
Vulnerable; First fixed in Release 15.0SE
12.2SG Not vulnerable
12.2(53)SG7; Available on 07-MAY-12
12.2SGA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SL Not vulnerable
Not vulnerable
12.2SM Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SO 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)SRE6
12.2STE Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SU Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2SV Not vulnerable
Releases up to and including 12.2(18)SV2 are not vulnerable.
12.2SVA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SVC 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 12.4T
12.2SX Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SXA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SXB Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SXD Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2SXE Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
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)SXI9
12.2SXJ Not vulnerable
12.2(33)SXJ2
12.2SY Not vulnerable
12.2(50)SY2; Available on 11-JUN-12
12.2SZ Not vulnerable
Vulnerable; First fixed in Release 12.0S
12.2T Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2TPC Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2XA Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XB Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XC Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XD Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XE Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XF Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XG Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XH Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XI Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XJ Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XK Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XL Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XM Not vulnerable
Vulnerable; First fixed in Release 15.0M
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.
12.2XQ Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XR Not vulnerable
Releases prior to 12.2(15)XR are vulnerable; Releases 12.2(15)XR and later are not vulnerable. First fixed in Release 15.0M
12.2XS Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XT Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XU Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XV Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2XW Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2YA Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2YC Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2YD Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2YE Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2YK Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2YO Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2YP Not vulnerable
Vulnerable; First fixed in Release 15.0M
Releases up to and including 12.2(8)YP are not vulnerable.
12.2YT Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2YW Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2YX Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2YY Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2YZ Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZB Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZC Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZD Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZE Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2ZH Not vulnerable
Vulnerable; First fixed in Release 15.0M
12.2ZJ Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZP Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZU Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
12.2ZX Not vulnerable
Vulnerable; First fixed in Release 12.2SRE
12.2ZY 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 March 2012 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 March 2012 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 March 2012 Cisco IOS Software Security Advisory Bundled Publication
15.0M Not vulnerable
15.0(1)M8
15.0MR Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.0MRA Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.0S Not vulnerable
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0(1)S5
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0SA Not vulnerable
Not vulnerable
15.0SE 15.0(1)SE1
15.0(1)SE1
15.0SG Not vulnerable
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0(2)SG2
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.0SY Not vulnerable
15.0(1)SY1
15.0XA Not vulnerable
Vulnerable; First fixed in Release 15.1T
15.0XO Cisco IOS XE devices: Please see Cisco IOS-XE Software Availability
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 March 2012 Cisco IOS Software Security Advisory Bundled Publication
15.1EY Not vulnerable
15.1(2)EY2
15.1GC Not vulnerable
15.1(2)GC2
15.1M 15.1(4)M4; Available on 30-MAR-12
15.1(4)M4; Available on 30-MAR-12
15.1MR Not vulnerable
Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
15.1S Not vulnerable
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.1(3)S2
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.1SG Not vulnerable
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
Not vulnerable
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
Not vulnerable
15.1T 15.1(3)T3
15.1(3)T3
15.1XB Not vulnerable
Vulnerable; First fixed in Release 15.1T
Affected 15.2-Based Releases First Fixed Release First Fixed Release for All Advisories in the March 2012 Cisco IOS Software Security Advisory Bundled Publication
15.2GC 15.2(1)GC2
15.2(1)GC2
15.2S Not vulnerable
Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.2(1)S1

Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
15.2T 15.2(1)T2
15.2(2)T1
15.2(3)T; Available on 30-MAR-12
15.2(1)T2
15.2(2)T1
15.2(3)T; Available on 30-MAR-12

* Cisco Catalyst 3550 Series Switches support the Internet Key Exchange (IKE) feature and are vulnerable to Cisco bug ID CSCts38429 when the devices are running Layer 3 images; however, this product reached the End of Software Maintenance milestone.  Cisco 3550 Series SMI Switches that are running Layer 2 images do not support IKE and are not vulnerable.  No other Cisco devices that run 12.2SE-based software are vulnerable.

 

Cisco IOS XE Software

Cisco IOS XE Software is not affected by the vulnerability disclosed in this advisory.

Cisco IOS XR Software

Cisco IOS XR Software is not affected by any of the vulnerabilities disclosed in the March 2012 Cisco IOS Software Security Advisory Bundled Publication.


Workarounds

In some versions of Cisco IOS Software, the Smart Install feature can be disabled with the global configuration command no vstack. In versions of Cisco IOS Software where this command is available, the vulnerability can be mitigated by disabling the Smart Install feature if it is not needed.

Note: The no vstack global configuration command to disable Smart Install was introduced with the fix for Cisco bug CSCtj75729 ("Ability to shut Smart Install default service on TCP port 4786"). If a Cisco IOS Software release supports the Smart Install feature but the no vstack command does not exist, the release does not contain the fix for Cisco bug CSCtj75729.

In versions of Cisco IOS Software that support only the Smart Install director functionality, Smart Install can be disabled with the no vstack basic global configuration command. This command also mitigates the vulnerability in cases where disabling Smart Install is operationally feasible.

If the Smart Install feature cannot be disabled because of operational constraints or because the no vstack command is not available, there are no workarounds. In this case, the only mitigation is to prevent TCP connections from untrusted sources to port 4786 on affected devices. Administrators can use the following mitigations on affected devices:

  • Interface access control lists (ACLs)
  • Control Plane Policing (CoPP; not available on all Cisco IOS Software releases)

Administrators can use the following mitigations on other devices in the network:

  • Infrastructure access control lists (iACLs)
  • VLAN access control lists (VACLs)

For information about additional mitigations that can be deployed on Cisco devices in the network, including iACLs and VACLs, refer to the Cisco Applied Mitigation Bulletin (AMB) companion document for this advisory, which is available at the following location: http://tools.cisco.com/security/center/content/CiscoAppliedMitigationBulletin/cisco-amb-20120328-smartinstall.

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, or as set forth at http://www.cisco.com/public/sw-center/sw-usingswc.shtml.

Do not contact psirt@cisco.com or security-alert@cisco.com for software upgrades.

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 Center on Cisco.com at http://www.cisco.com.

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 issue was reported to Cisco by customers who discovered it during the course of security audits.

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 Intelligence Operations at the following link

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120328-smartinstall

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 1.1 2012-April-06 Provided additional method to determine Smart Install status via the "show tcp brief all" command. Clarified that Smart Install is enabled by default on devices that can act as directors and clients, and disabled by default on devices that can act only as directors. Clarified that the "no vstack" command (proposed as a workaround) is not available in all Cisco IOS Software releases. Mentioned that "no vstack basic" disables Smart Install on devices that support only the Smart Install director role. Mentioned that filtering TCP traffic destined to port 4786 of an affected device can be used as a mitigation.
Revision 1.0 2012-March-28 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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