Cisco Security Advisory: Cisco IOS Software Smart Install Remote Code Execution Vulnerability

28 Sep 2011

A vulnerability exists in the Smart Install feature of Cisco Catalyst
Switches running Cisco IOS Software that could allow an
unauthenticated, remote attacker to perform remote code execution on
the affected device.

Cisco has released free software updates that address this
vulnerability.

There are no workarounds available to mitigate this vulnerability
other than disabling the Smart Install feature.

This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20110928-smart-install.shtml.

Note: The September 28, 2011, Cisco IOS Software Security Advisory
bundled publication includes ten Cisco Security Advisories. Nine of the
advisories address vulnerabilities in Cisco IOS Software, and one
advisory addresses a vulnerability in Cisco Unified Communications
Manager. 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 September 2011 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_sep11.html

Affected Products
=================

This vulnerability only affects Cisco Catalyst Switches and Cisco
Integrated Services Routers with the Smart Install feature enabled.

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 the show commands are different
when entered on the director or on the client. The following is the
output of the "show vstack config" in a device 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 the "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)

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 the white paper Cisco
IOS and NX-OS Software Reference Guide available 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 switches and
Cisco Integrated Services Routers. This means that a customer can
ship a device to a location, place it in the network and power it on
with no configuration required on the device.

A vulnerability exists in the Smart Install feature of Cisco Catalyst
Switches running Cisco IOS Software that could allow an
unauthenticated, remote attacker to perform remote code execution on
the affected device. Smart Install uses TCP port 4786 for
communication. An established TCP connection with a completed TCP
three-way handshake is needed to be able to trigger this
vulnerability.

This vulnerability is documented in Cisco bug ID CSCto10165, and
has been assigned Common Vulnerabilities and Exposures (CVE) ID
CVE-2011-3271.

Vulnerability Scoring Details
=============================

Cisco has provided scores for the vulnerability in this advisory
based on the Common Vulnerability Scoring System (CVSS). The CVSS
scoring in this Security Advisory is done in accordance with CVSS
version 2.0.

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

Cisco has provided a base and temporal score. Customers can then
compute environmental scores to assist in determining the impact of
the vulnerability in individual networks.

Cisco has provided an FAQ to answer additional questions regarding
CVSS at:

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

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

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

* CSCto10165 ("Smart Install Crashes with certain IP Packets")

CVSS Base Score - 10.0
    Access Vector -            Network
    Access Complexity -        Low
    Authentication -           None
    Confidentiality Impact -   Complete
    Integrity Impact -         Complete
    Availability Impact -      Complete

CVSS Temporal Score - 8.3
    Exploitability -           Functional
    Remediation Level -        Official-Fix
    Report Confidence -        Confirmed

Impact
======

Successful exploitation could allow an unauthenticated, remote
attacker to perform remote code execution on the affected device.

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.

Additionally, the Cisco IOS Software Checker is available on
the Cisco Security Intelligence Operations (SIO) portal at
http://tools.cisco.com/security/center/selectIOSVersion.x. It provides
several features for checking which Security Advisories affect specified
versions of Cisco IOS Software.

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 For This Advisory column. The First Fixed Release for All
Advisories in the September 2011 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.

+------------------------------------------------------------+
|   Major    |         Availability of Repaired Releases     |
|  Release   |                                               |
|------------+-----------------------------------------------|
|  Affected  |  First Fixed   | First Fixed Release for All  |
| 12.0-Based |    Release     | Advisories in the September  |
|  Releases  |                |   2011 Bundled Publication   |
|------------------------------------------------------------|
| There are no affected 12.0 based releases                  |
|------------------------------------------------------------|
|  Affected  |  First Fixed   | First Fixed Release for All  |
| 12.1-Based |    Release     | Advisories in the September  |
|  Releases  |                |   2011 Bundled Publication   |
|------------------------------------------------------------|
| There are no affected 12.1 based releases                  |
|------------------------------------------------------------|
|  Affected  |  First Fixed   | First Fixed Release for All  |
| 12.2-Based |    Release     | Advisories in the September  |
|  Releases  |                |   2011 Bundled Publication   |
|------------+----------------+------------------------------|
| 12.2       | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2B      | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2BC     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2BW     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2BX     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SB               |
|------------+----------------+------------------------------|
| 12.2BY     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2BZ     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2CX     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2CY     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2CZ     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SB               |
|------------+----------------+------------------------------|
| 12.2DA     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2DD     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2DX     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2EU     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            |                | Releases up to and including |
| 12.2EW     | Not vulnerable | 12.2(20)EW4 are not          |
|            |                | vulnerable.                  |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2EWA    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2EX     | 12.2(55)EX3    | 12.2(55)EX3                  |
|------------+----------------+------------------------------|
| 12.2EY     | 12.2(58)EY     | 12.2(58)EY                   |
|------------+----------------+------------------------------|
|            | Vulnerable;    |                              |
|            | migrate to any |                              |
|            | release in     |                              |
|            | 15.0SE         |                              |
| 12.2EZ     |                | Vulnerable; migrate to any   |
|            | Releases up to | release in 15.0SE            |
|            | and including  |                              |
|            | 12.2(53)EZ are |                              |
|            | not            |                              |
|            | vulnerable.    |                              |
|------------+----------------+------------------------------|
| 12.2FX     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SE               |
|------------+----------------+------------------------------|
| 12.2FY     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2EX               |
|------------+----------------+------------------------------|
| 12.2FZ     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SE               |
|------------+----------------+------------------------------|
| 12.2IRA    | Not vulnerable | Vulnerable; migrate to any   |
|            |                | release in 12.2IRG           |
|------------+----------------+------------------------------|
| 12.2IRB    | Not vulnerable | Vulnerable; migrate to any   |
|            |                | release in 12.2IRG           |
|------------+----------------+------------------------------|
| 12.2IRC    | Not vulnerable | Vulnerable; migrate to any   |
|            |                | release in 12.2IRG           |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IRD    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IRE    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2IRF    | Not vulnerable | Vulnerable; migrate to any   |
|            |                | release in 12.2IRG           |
|------------+----------------+------------------------------|
| 12.2IRG    | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IXA    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IXB    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IXC    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IXD    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IXE    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IXF    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IXG    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2IXH    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2JA     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2JK     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2MB     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2MC     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2MRA    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SRD              |
|------------+----------------+------------------------------|
| 12.2MRB    | Not vulnerable | 12.2(33)MRB5                 |
|------------+----------------+------------------------------|
|            |                | Releases prior to 12.2(30)S  |
|            |                | are vulnerable; Releases     |
| 12.2S      | Not vulnerable | 12.2(30)S and later are not  |
|            |                | vulnerable. First fixed in   |
|            |                | Release 12.2SB               |
|------------+----------------+------------------------------|
|            |                | 12.2(31)SB20                 |
| 12.2SB     | Not vulnerable |                              |
|            |                | 12.2(33)SB10                 |
|------------+----------------+------------------------------|
| 12.2SBC    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SB               |
|------------+----------------+------------------------------|
| 12.2SCA    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SCC              |
|------------+----------------+------------------------------|
| 12.2SCB    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SCC              |
|------------+----------------+------------------------------|
| 12.2SCC    | Not vulnerable | 12.2(33)SCC7                 |
|------------+----------------+------------------------------|
| 12.2SCD    | Not vulnerable | 12.2(33)SCD6                 |
|------------+----------------+------------------------------|
|            |                | 12.2(33)SCE1                 |
| 12.2SCE    | Not vulnerable |                              |
|            |                | 12.2(33)SCE2                 |
|------------+----------------+------------------------------|
| 12.2SCF    | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            | Releases up to | 12.2(55)SE3                  |
| 12.2SE     | and including  |                              |
|            | 12.2(54)SE are | 12.2(58)SE                   |
|            | not vulnerable |                              |
|------------+----------------+------------------------------|
| 12.2SEA    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SE               |
|------------+----------------+------------------------------|
| 12.2SEB    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SE               |
|------------+----------------+------------------------------|
| 12.2SEC    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SE               |
|------------+----------------+------------------------------|
| 12.2SED    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SE               |
|------------+----------------+------------------------------|
| 12.2SEE    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SE               |
|------------+----------------+------------------------------|
| 12.2SEF    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SE               |
|------------+----------------+------------------------------|
|            |                | Releases prior to 12.2(25)   |
|            |                | SEG4 are vulnerable;         |
| 12.2SEG    | Not vulnerable | Releases 12.2(25)SEG4 and    |
|            |                | later are not vulnerable.    |
|            |                | First fixed in Release       |
|            |                | 12.2EX                       |
|------------+----------------+------------------------------|
|            |                | Releases prior to 12.2(53)   |
| 12.2SG     | Not vulnerable | SG4 are vulnerable; Releases |
|            |                | 12.2(53)SG4 and later are    |
|            |                | not vulnerable.              |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2SGA    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2SL     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2SM     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2SO     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2SQ     | Not vulnerable | 12.2(50)SQ3                  |
|------------+----------------+------------------------------|
| 12.2SRA    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SRD              |
|------------+----------------+------------------------------|
| 12.2SRB    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SRD              |
|------------+----------------+------------------------------|
| 12.2SRC    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SRD              |
|------------+----------------+------------------------------|
| 12.2SRD    | Not vulnerable | 12.2(33)SRD6                 |
|------------+----------------+------------------------------|
| 12.2SRE    | Not vulnerable | 12.2(33)SRE4                 |
|------------+----------------+------------------------------|
| 12.2STE    | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2SU     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
|            |                | Releases prior to 12.2(29a)  |
|            |                | SV are vulnerable; Releases  |
| 12.2SV     | Not vulnerable | 12.2(29a)SV and later are    |
|            |                | not vulnerable. Migrate to   |
|            |                | any release in 12.2SVD       |
|------------+----------------+------------------------------|
| 12.2SVA    | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2SVC    | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2SVD    | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2SVE    | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2SW     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2SX     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SXF              |
|------------+----------------+------------------------------|
| 12.2SXA    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SXF              |
|------------+----------------+------------------------------|
| 12.2SXB    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SXF              |
|------------+----------------+------------------------------|
| 12.2SXD    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SXF              |
|------------+----------------+------------------------------|
| 12.2SXE    | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SXF              |
|------------+----------------+------------------------------|
| 12.2SXF    | Not vulnerable | 12.2(18)SXF17b               |
|------------+----------------+------------------------------|
| 12.2SXH    | Not vulnerable | 12.2(33)SXH8a                |
|------------+----------------+------------------------------|
| 12.2SXI    | Not vulnerable | 12.2(33)SXI6                 |
|------------+----------------+------------------------------|
| 12.2SXJ    | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2SY     | Not vulnerable | 12.2(50)SY                   |
|------------+----------------+------------------------------|
| 12.2SZ     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SB               |
|------------+----------------+------------------------------|
| 12.2T      | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2TPC    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2XA     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XB     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2XC     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XD     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XE     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XF     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XG     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XH     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XI     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XJ     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XK     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XL     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XM     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XN     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            | Please see     |                              |
| 12.2XNA    | Cisco IOS-XE   | Please see Cisco IOS-XE      |
|            | Software       | Software Availability        |
|            | Availability   |                              |
|------------+----------------+------------------------------|
|            | Please see     |                              |
| 12.2XNB    | Cisco IOS-XE   | Please see Cisco IOS-XE      |
|            | Software       | Software Availability        |
|            | Availability   |                              |
|------------+----------------+------------------------------|
|            | Please see     |                              |
| 12.2XNC    | Cisco IOS-XE   | Please see Cisco IOS-XE      |
|            | Software       | Software Availability        |
|            | Availability   |                              |
|------------+----------------+------------------------------|
|            | Please see     |                              |
| 12.2XND    | Cisco IOS-XE   | Please see Cisco IOS-XE      |
|            | Software       | Software Availability        |
|            | Availability   |                              |
|------------+----------------+------------------------------|
|            | Please see     |                              |
| 12.2XNE    | Cisco IOS-XE   | Please see Cisco IOS-XE      |
|            | Software       | Software Availability        |
|            | Availability   |                              |
|------------+----------------+------------------------------|
|            | Please see     |                              |
| 12.2XNF    | Cisco IOS-XE   | Please see Cisco IOS-XE      |
|            | Software       | Software Availability        |
|            | Availability   |                              |
|------------+----------------+------------------------------|
|            |                | Releases prior to 12.2(54)XO |
| 12.2XO     | Not vulnerable | are vulnerable; Releases     |
|            |                | 12.2(54)XO and later are not |
|            |                | vulnerable.                  |
|------------+----------------+------------------------------|
| 12.2XQ     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XR     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XS     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XT     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XU     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XV     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2XW     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2YA     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2YB     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2YC     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2YD     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2YE     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YF     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YG     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YH     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YJ     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2YK     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YL     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2YM     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YN     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2YO     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2YP     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YQ     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YR     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YS     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YT     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YU     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YV     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YW     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YX     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YY     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2YZ     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2ZA     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SXF              |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2ZB     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2ZC     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2ZD     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2ZE     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2ZF     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2ZG     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2ZH     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.4                 |
|------------+----------------+------------------------------|
| 12.2ZJ     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2ZL     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 12.2ZP     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
| 12.2ZU     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 12.2SXH              |
|------------+----------------+------------------------------|
| 12.2ZX     | Not vulnerable | Not vulnerable               |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2ZY     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 12.2ZYA    | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|  Affected  |  First Fixed   | First Fixed Release for All  |
| 12.3-Based |    Release     | Advisories in the September  |
|  Releases  |                |   2011 Bundled Publication   |
|------------------------------------------------------------|
| There are no affected 12.3 based releases                  |
|------------------------------------------------------------|
|  Affected  |  First Fixed   | First Fixed Release for All  |
| 12.4-Based |    Release     | Advisories in the September  |
|  Releases  |                |   2011 Bundled Publication   |
|------------------------------------------------------------|
| There are no affected 12.4 based releases                  |
|------------------------------------------------------------|
|  Affected  |  First Fixed   | First Fixed Release for All  |
| 15.0-Based |    Release     | Advisories in the September  |
|  Releases  |                |   2011 Bundled Publication   |
|------------------------------------------------------------|
| There are no affected 15.0 based releases                  |
|------------------------------------------------------------|
|  Affected  |  First Fixed   | First Fixed Release for All  |
| 15.1-Based |    Release     | Advisories in the September  |
|  Releases  |                |   2011 Bundled Publication   |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 15.1EY     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
| 15.1GC     | Not vulnerable | Vulnerable; First fixed in   |
|            |                | Release 15.1T                |
|------------+----------------+------------------------------|
|            | 15.1(4)M2;     | 15.1(4)M2; Available on      |
| 15.1M      | Available on   | 30-SEP-11                    |
|            | 30-SEP-11      |                              |
|------------+----------------+------------------------------|
|            |                | Vulnerable; contact your     |
|            |                | support organization per the |
| 15.1MR     | Not vulnerable | instructions in the          |
|            |                | Obtaining Fixed Software     |
|            |                | section of this advisory.    |
|------------+----------------+------------------------------|
|            |                | 15.1(2)S2                    |
| 15.1S      | Not vulnerable |                              |
|            |                | 15.1(3)S                     |
|------------+----------------+------------------------------|
|            |                | 15.1(2)T4                    |
| 15.1T      | 15.1(3)T2      |                              |
|            |                | 15.1(1)T4 on 8-Dec-2011      |
|------------+----------------+------------------------------|
|            | Vulnerable;    |                              |
|            | First fixed in |                              |
|            | Release 15.1T  |                              |
|            |                | Vulnerable; First fixed in   |
| 15.1XB     | Releases up to | Release 15.1T                |
|            | and including  |                              |
|            | 15.1(1)XB are  |                              |
|            | not            |                              |
|            | vulnerable.    |                              |
|------------+----------------+------------------------------|
|  Affected  |  First Fixed   | First Fixed Release for All  |
| 15.2-Based |    Release     | Advisories in the September  |
|  Releases  |                |   2011 Bundled Publication   |
|------------------------------------------------------------|
| There are no affected 15.2 based releases                  |
+------------------------------------------------------------+

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 the vulnerability disclosed
in this advisory.

Cisco IOS XR Software is not affected by the vulnerabilities
disclosed in the September 28, 2011, Cisco IOS Software Security
Advisory bundled publication.

Workarounds
===========

There are no workarounds available to mitigate this vulnerability
other than disabling the Smart Install feature. The Smart Install
Feature is enabled by default in client switches. No configuration is
needed in client switches.

If Smart Install feature is not required, and the device supports
the configuration command "no vstack" as introduced by Cisco Bug
ID CSCtj75729, then disabling Smart Install, with the "no vstack"
configuration command mitigates this vulnerability.

Additional mitigations that can be deployed on Cisco devices within the
network are available in the Cisco Applied Mitigation Bulletin companion
document for this advisory, which is available at the following link:

http://www.cisco.com/warp/public/707/cisco-amb-20110928-smart-install.shtml

Obtaining Fixed Software
========================

Cisco has released free software updates that address this
vulnerability. Prior to deploying software, customers should consult
their maintenance provider or check the software for feature set
compatibility and known issues specific to their environment.

Customers may only install and expect support for the feature
sets they have purchased. By installing, downloading, accessing
or otherwise using such software upgrades, customers agree to be
bound by the terms of Cisco's software license terms found at
http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html,
or as otherwise set forth at Cisco.com Downloads 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, this means that
upgrades should be obtained through the Software Center on Cisco's
worldwide website at http://www.cisco.com.

Customers using Third Party Support Organizations
+------------------------------------------------

Customers whose Cisco products 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 support organization for guidance and assistance
with the appropriate course of action in regards to this advisory.

The effectiveness of any workaround or fix is dependent on specific
customer situations, such as product mix, network topology, traffic
behavior, and organizational mission. Due to the variety of affected
products and releases, customers should consult with their service
provider or support organization to ensure any applied workaround or
fix is the most appropriate for use in the intended network before it
is deployed.

Customers without Service Contracts
+----------------------------------

Customers who purchase direct from Cisco but do not hold a Cisco
service contract, and customers who purchase through third-party
vendors but are unsuccessful in obtaining fixed software through
their point of sale should acquire upgrades by contacting the Cisco
Technical Assistance Center (TAC). TAC contacts are as follows.

  * +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 their product serial number available and be
prepared to give the URL of this notice as evidence of entitlement to
a free upgrade. Free upgrades for non-contract customers must be
requested through the TAC.

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

Exploitation and Public Announcements
=====================================

The Cisco PSIRT is not aware of any public announcements or malicious
use of the vulnerability described in this advisory.

This vulnerability was discovered and reported to Cisco by Greg Jones
of Digital Assurance.

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's worldwide website at:

http://www.cisco.com/warp/public/707/cisco-sa-20110928-smart-install.shtml

In addition to worldwide web posting, a text version of this notice
is clear-signed with the Cisco PSIRT PGP key and is posted to the
following e-mail and Usenet news recipients.

  * 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
  * comp.dcom.sys.cisco@newsgate.cisco.com

Future updates of this advisory, if any, will be placed on Cisco's
worldwide website, but may or may not be actively announced on
mailing lists or newsgroups. Users concerned about this problem are
encouraged to check the above URL for any updates.

Revision History
================

+------------------------------------------------------------+
| Revision 1.0 | 2011-September-28 | Initial public release  |
+------------------------------------------------------------+

Cisco Security Procedures
=========================

Complete information on reporting security vulnerabilities in Cisco
products, obtaining assistance with security incidents, and
registering to receive security information from Cisco, is available
on Cisco's worldwide website at http://www.cisco.com/en/US/products/
products_security_vulnerability_policy.html. This includes
instructions for press inquiries regarding Cisco security notices.
All Cisco security advisories are available at http://www.cisco.com/
go/psirt.

+--------------------------------------------------------------------
Copyright 2010-2011 Cisco Systems, Inc. All rights reserved.
+--------------------------------------------------------------------

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Cisco Security Advisory: Cisco IOS Software Smart Install Remote Code Execution Vulnerability

Cisco Systems Product Security Incident Response Team