Cisco Security Advisory: Cisco IOS Firewall Authentication Proxy for FTP and Telnet Sessions Buffer Overflow

7 Sep 2005

The Cisco IOS Firewall Authentication Proxy for FTP and/or Telnet 
Sessions feature in specific versions of Cisco IOS software is 
vulnerable to a remotely-exploitable buffer overflow condition.

Devices that do not support, or are not configured for Firewall 
Authentication Proxy for FTP and/or Telnet Services are not affected.

Devices configured with only Authentication Proxy for HTTP and/or 
HTTPS are not affected.

Only devices running certain versions of Cisco IOS are affected.

Cisco has made free software available to address this vulnerability. 
There are workarounds available to mitigate the effects of the 
vulnerability. 

This advisory is available at
http://www.cisco.com/warp/public/707/cisco-sa-20050907-auth_proxy.shtml.

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

Vulnerable Products
+------------------

Devices that are running the following release trains of Cisco IOS are
affected if Firewall Authentication Proxy for FTP and/or Telnet 
Sessions is configured and applied to an active interface.

    * 12.2ZH and 12.2ZL based trains
    * 12.3 based trains
    * 12.3T based trains
    * 12.4 based trains
    * 12.4T based trains

To determine the software running on a Cisco product, log in to the
device and issue the show version command to display the system
banner. Cisco IOS software will identify itself as "Internetwork
Operating System Software" or simply "IOS." On the next line of output,
the image name will be displayed between parentheses, followed by
"Version" and the Cisco IOS release name. Other Cisco devices will not
have the show version command, or will give different output.

The following example identifies a Cisco 7200 router running Cisco IOS
release 12.3(10a) with an installed image name of C7200-JK8O3S-M.

Router#show version
Cisco Internetwork Operating System Software 
IOS (tm) 7200 Software (C7200-JK8O3S-M), Version 12.3(10a), RELEASE SOFTWARE (fc2)
Copyright (c) 1986-2004 by cisco Systems, Inc.

Additional information about Cisco IOS release naming can be found at
http://www.cisco.com/warp/public/620/1.html.

Refer to the Details section for more information about affected and 
unaffected configurations.

Products Confirmed Not Vulnerable
+--------------------------------

    * Products that are not running Cisco IOS are not affected
    * Products that are running Cisco IOS versions 12.2 and earlier
      (including 12.0S) are not affected. (excluding 12.2ZH and 12.2ZL)
    * Products that are running Cisco IOS are not affected unless they
      are configured for Firewall Authentication Proxy for FTP and/or
      Telnet Sessions.
    * Products that are running Cisco IOS XR are not affected.

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

Details
=======

The Cisco IOS Firewall Authentication Proxy feature allows network
administrators to apply specific security policies on a per-user basis.
With the Firewall Authentication Proxy for FTP and/or Telnet Sessions
feature, users can log into the network services via FTP and/or Telnet,
and their specific access profiles are automatically retrieved and
applied from a Remote Authentication Dial In User Service (RADIUS), or
Terminal Access Controller Access Control System Plus (TACACS+)
authentication server.

Cisco IOS Software is vulnerable to a Denial of Service (DoS) and 
potentially an arbitrary code execution attack when processing the 
user authentication credentials from an Authentication Proxy Telnet/FTP 
session.  To exploit this vulnerability an attacker must first complete
a TCP connection to the IOS device running affected software and 
receive an auth-proxy authentication prompt.

This vulnerability is documented in the Cisco Bug Toolkit as Bug ID
CSCsa54608 (registered customers only)

To determine if your device is running Firewall Authentication Proxy for
FTP and/or Telnet Sessions feature, log into the device and issue the
show ip auth-proxy configuration command to display the configuration
of Firewall Authentication Proxy services. The following example
identifies Firewall Authentication Proxy services running for Telnet and
FTP under the proxy rule name proxy_example.

Router#show ip auth-proxy configuration 
Authentication global cache time is 60 minutes
Authentication global absolute time is 0 minutes
Authentication Proxy Watch-list is disabled

Authentication Proxy Rule Configuration
Auth-proxy name proxy_example
	ftp list not specified auth-cache-time 60 minutes
	telnet list not specified auth-cache-time 60 minutes

The following will be seen if Firewall Authentication Proxy services are
not enabled but supported in your IOS version:

Router#show ip auth-proxy configuration 
Authentication global cache time is 60 minutes
Authentication global absolute time is 0 minutes
Authentication Proxy Watch-list is disabled

Router# 

The following will be seen if running a version of IOS that does not
support Firewall Authentication Proxy services:

Router#show ip auth-proxy configuration
                ^
% Invalid input detected at '^' marker.

Router#

A router that has Firewall Authentication Proxy services assigned to an
interface will have ip auth-proxy <list name> command under an
interface in the show running-config output.

The following example identifies Firewall Authentication Proxy services
running under the proxy rule name "proxy_example" applied to the
interface Ethernet 2/1:

Router#show ip auth-proxy configuration 
Authentication global cache time is 60 minutes
Authentication global absolute time is 0 minutes
Authentication Proxy Watch-list is disabled

Authentication Proxy Rule Configuration
Auth-proxy name proxy_example
    	ftp list not specified auth-cache-time 60 minutes
	telnet list not specified auth-cache-time 60 minutes

Router#show running-config
!
!
!
interface Ethernet2/1
 ip address 10.1.1.1 255.255.255.0
 ip auth-proxy proxy_example
!
!
!

Additional information about Cisco IOS Firewall Authentication Proxy
services refer to:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120....

Additional information about Cisco IOS Firewall Authentication Proxy for
FTP and/or Telnet Sessions refer to:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123...

Impact
======

Successful exploitation of the vulnerability on Cisco IOS may result
in a reload of the device or execution of arbitrary code. Repeated 
exploitation could result in a sustained DoS attack or execution of 
arbitrary code on Cisco IOS devices.

Software Versions and Fixes
===========================

When considering software upgrades, please also consult
http://www.cisco.com/en/US/products/products_security_advisories_listing.htm...
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") for assistance.

Each row of the Cisco IOS software table (below) describes a release
train and the platforms or products for which it is intended. If a given
release train is vulnerable, then the earliest possible releases that
contain the fix (the "First Fixed Release") and the anticipated date of
availability for each are listed in the "Rebuild" and "Maintenance"
columns. A device running a release in the given train that is earlier
than the release in a specific column (less than the First Fixed
Release) is known to be vulnerable. The release should be upgraded at
least to the indicated release or a later version (greater than or 
equal to the First Fixed Release label).

For further information on the terms "Rebuild" and "Maintenance",
please consult the following URL:
http://www.cisco.com/warp/public/620/1.html

+----------------------------------------+
|   Major    | Availability of Repaired  |
|  Release   |         Releases          |
|------------+---------------------------|
| Affected   |             |             |
| 12.2-Based | Rebuild     | Maintenance |
| Release    |             |             |
|------------+-------------+-------------|
|12.2ZH      | Vulnerable; contact TAC   |
|------------|-------------+-------------|
|            | Vulnerable; migrate to    |
|            | 12.3(4)XK4 or later for   |
|            | Cisco 17xx;               |
|12.2ZL      | Migrate to 12.4(1) or     |
|            | later for Cisco 3200;     |
|            | Migrate to 12.3(7)XR4 or  |
|            | later for ICS7750         |
|------------|-------------+-------------|
| Affected   |             |             |
| 12.3-Based | Rebuild     | Maintenance |
| Release    |             |             |
|------------+-------------+-------------|
|            | 12.3(3h)	   |             |
|            |-------------+-------------|
|            | 12.3(5e)    |             |
|12.3        |-------------+-------------|
|            | 12.3(6e)    |             |
|            |-------------+-------------|
|            | 12.3(9d)    |             |
|            |-------------+-------------|
|            | 12.3(10d)   |             |
|            |-------------+-------------|
|            | 12.3(12b)   |             |
|            |-------------+-------------|
|            | 12.3(13a)   | 12.3(15)    |
|------------|-------------+-------------|
|12.3B       | Vulnerable; migrate to    |
|            | 12.3(14)T2 or later       |
|------------|-------------+-------------|
|12.3BC      | 12.3(9a)BC7; available    |
|            | 19-Sept-05                |
|------------|-------------+-------------|
|12.3BW      | Vulnerable; migrate to    |
|            | 12.3(14)T2 or later       |
|------------|-------------+-------------|
|12.3JA      |             | 12.3(7)JA   |
|------------|-------------+-------------|
|12.3JK      |             | 12.3(2)JK   |
|----------------------------------------|
|            | 12.3(7)T10  |             |
|            |---------------------------|
|            | 12.3(8)T9   |             |
|12.3T       |-------------|-------------|
|            | 12.3(11)T6  |             |
|            |---------------------------|
|            | 12.3(14)T2  |             |
|----------------------------------------|
|12.3XA      | 12.3(2)XA5; available TBD |
|------------|-------------+-------------|
|12.3XB      | Vulnerable; migrate to    |
|            | 12.3(14)T2 or later       |
|------------|-------------+-------------|
|12.3XC      | 12.3(2)XC3  |             |
|------------|-------------+-------------|
|12.3XD      | Vulnerable; migrate to    |
|            | 12.3(14)T2 or later       |
|------------|-------------+-------------|
|12.3XE      | 12.3(2)XE4; available TBD |
|------------|-------------+-------------|
|12.3XF      | Vulnerable; migrate to    |
|            | 12.3(14)T2 or later       |
|------------|-------------+-------------|
|12.3XG      | 12.3(4)XG5; available TBD |
|------------|-------------+-------------|
|12.3XH      | Vulnerable; migrate to    |
|            | 12.3(14)T2 or later       |
|------------|-------------+-------------|
|12.3XI      | 12.3(7)XI4  |             |
|--------------------------+-------------|
|12.3XJ      | Vulnerable; migrate to    |
|            | 12.3(11)YF2 or later      |
|----------------------------------------|
|12.3XK      | 12.3(4)XK4; available TBD |
|------------|---------------------------|
|12.3XL      | 12.3(11)XL3 |             |
|------------|---------------------------|
|12.3XM      | Vulnerable; migrate to    |
|            | 12.3(14)T2 or later       |
|------------|---------------------------|
|12.3XQ      | Vulnerable; migrate to    |
|            | 12.4(1) or later          |
|------------|-------------+-------------|
|12.3XR      | 12.3(7)XR4  |             |
|----------------------------------------|
|12.3XS      | Vulnerable; migrate to    |
|            | 12.4(1) or later          |
|------------|---------------------------|
|12.3XU      | Vulnerable; contact TAC   |
|------------|---------------------------|
|12.3XW      | Vulnerable; migrate to    |
|            | 12.3(11)YF2 or later      |
|----------------------------------------|
|12.3XY      | Vulnerable; contact TAC   |
|------------|---------------------------|
|            | Vulnerable; migrate to    |
|            | 12.4(1) or later for Cisco| 
|12.3YA      | 828; migrate to 12.3(8)YG2| 
|            | or later for SOHO 9x and  |
|            | Cisco 83x                 |
|------------|---------------------------|
|12.3YD      | Vulnerable; migrate to    |
|            | 12.3(14)T2 or later       |
|----------------------------------------|
|12.3YF      | 12.3(11)YF2  |            |
|----------------------------------------|
|12.3YG      | 12.3(8)YG2   |            |
|----------------------------------------|
|12.3YI      | 12.3(8)YI1   |            |
|----------------------------------------|
|12.3YJ      | Vulnerable; contact TAC   |
|----------------------------------------|
|12.3YK      | 12.3(11)YK1  |            |
|----------------------------------------|
|12.3YQ      |              | 12.3(14)YQ |
|----------------------------------------|
|12.3YS      |              | 12.3(11)YS |
|----------------------------------------|
|12.3YT      |              | 12.3(14)YT |
|----------------------------------------|
|12.3YU      |              | 12.3(14)YU |
|----------------------------------------|
|12.3YW      |              | 12.3(11)YW |
|----------------------------------------|
| Affected   |             |             |
| 12.4-Based | Rebuild     | Maintenance |
| Release    |             |             |
|------------+-------------+-------------|
|12.4        |             | 12.4(1)     |
|----------------------------------------|
|12.4MR      |             | 12.4(2)MR   |
|----------------------------------------|
|12.4T       |             | 12.4(2)T    |
+----------------------------------------+

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

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 agreement with third-party support organizations such as
Cisco Partners, authorized resellers, or service providers should
contact that support organization for assistance with the upgrade, 
which should be free of charge.

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

Customers who purchase direct from Cisco but who do not hold a Cisco
service contract and customers who purchase through third-party vendors
but are unsuccessful at obtaining fixed software through their point of
sale should get their 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 

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

Please do not contact either "psirt@cisco.com" or
"security-alert@cisco.com" for software upgrades.

See http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml for
additional TAC contact information, including special localized
telephone numbers and instructions and e-mail addresses for use in
various languages.

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/public/sw-license-agreement.html, or as otherwise
set forth at Cisco.com Downloads at
http://www.cisco.com/public/sw-center/sw-usingswc.shtml.

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

The effectiveness of any workaround 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 is the most
appropriate for use in the intended network before it is deployed.

Disable Cisco IOS Firewall Authentication Proxy feature for Telnet/FTP sessions
+------------------------------------------------------------------------------

In networks where Cisco IOS Firewall Authentication Proxy feature for 
Telnet/FTP sessions is not required but enabled, disabling the feature on 
an IOS device will eliminate exposure to this vulnerability. On a router 
which is configured for Cisco IOS Firewall Authentication Proxy feature 
for Telnet/FTP sessions, this must be done by issuing the command:

"no ip auth-proxy name 'auth-proxy-name' {ftp | telnet}" 

Deploy Cisco IOS Firewall Authentication Proxy feature for HTTP/HTTPS sessions
+-----------------------------------------------------------------------------
Configure the device with Cisco IOS Firewall Authentication Proxy feature 
for HTTP and/or HTTPS sessions and allow the Telnet and FTP services 
within the per-user TACACS+/RADIUS profile. Disable Authentication 
proxy for Telnet/FTP sessions to eliminate exposure.

An example of the configuration statements for HTTP session Auth-proxy is:

         ! Configure auth-proxy for http session authentication
         ip auth-proxy name http-proxy http
         ! Configure the router's web server to service auth-proxy authentication attempts
         ip http server
         ! Set the HTTP server authentication method to AAA
         ip http authentication aaa

Additional auth-proxy and web server configuration settings are available. 
For details see:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120...

After successful authentication via HTTP/HTTPS, the user can initiate 
required FTP or Telnet sessions. The example shown below for Cisco 
Secure Windows (TACACS+) server profile Group setting allows FTP and 
Telnet as part of access-list entry proxyacl#2=permit tcp any any

         priv-lvl=15
         proxyacl#1=permit icmp any any
         proxyacl#2=permit tcp any any
         proxyacl#3=permit udp any any

Mitigations
===========

Not all of the mitigation strategies listed will work for all customers.
Some of the workarounds listed are dependent on which versions and 
feature-sets of IOS you have in your network.  These mitigation strategies,
may help reduce exposure to this vulnerability. 
To eliminate exposure to this vulnerability, customers should apply one
of the workarounds listed above, or upgrade to a fixed release of Cisco 
IOS.

Access Control Lists (ACLs)
+--------------------------
Deploying IP access-lists can mitigate the effects of this vulnerability 
by allowing Firewall Authentication Proxy access only from trusted 
subnets. This feature must be used in conjunction with interface 
access-lists to ensure that IP traffic from un-trusted subnets is 
dropped by the router and not forwarded around the auth-proxy feature. 
Once the IP access-list is created, it is applied to the Authentication
proxy by adding the keyword "list" followed by the IP access-list name or
number. In the example below the trusted network is 169.160.160.0/24 and
the auth-proxy router interface is 10.66.65.47. Example:

         ! Permit trusted network 169.160.160.0/24 to access auth-proxy
         access-list 105 permit tcp 169.160.160.0 0.0.0.255 any eq telnet
         !
         ! Deny all IP traffic that is not authenticated by auth-proxy
         ! Note: Management and Control traffic to the router itself would 
         !       need to be allowed in this access-list
         access-list 106 deny ip any any
         !
         ! Modify the telnet auth-proxy config to use access-list 105
         ip auth-proxy name tel-proxy telnet inactivity-time 60 list 105
         !
         ! Apply interface access-list 106 and auth-proxy test
         interface FastEthernet1/0
         ip address 10.66.65.47 255.255.255.0
         ip access-group 106 in
         ip auth-proxy tel-proxy

For further information on creating IP access lists see
Protecting Your Core: Infrastructure Protection Access Control Lists
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00...

and

Transit Access Control Lists: Filtering at Your Edge
http://www.cisco.com/warp/public/707/tacl.html

Control Plane Policing
+---------------------
The Control Plane Policy (CoPP) feature can be used to mitigate the 
effects of this vulnerability by only allowing trusted hosts to attempt
connections through the auth-proxy router.

Care must be taken to ensure that legitimate management connections to
the auth-proxy router itself are not dropped by the CoPP policy.

In the following example trusted management host 169.160.160.1 is allowed 
to establish Telnet connections to the auth-proxy router itself.
Trusted network 169.160.160.0/24 is allowed to attempt FTP and Telnet 
auth-proxy connections to IP networks and addresses other than the 
auth-proxy router itself. All other inbound FTP and Telnet connections 
attempts are denied.

The auth-proxy router's IP addresses are 172.16.1.1 (Internet Side), 
1.1.1.1/24 and 10.66.65.47 (Internal).  Telnet/FTP server is 172.168.1.1.

         ! Do not police Telnet from trusted management host 169.160.160.1 to the auth-proxy 
         ! router

         access-list 105 remark ** Do not police telnet from Trusted Hosts to Auth-Proxy Router **
         access-list 105 deny tcp host 169.160.160.1 host 172.16.1.1 eq telnet
         access-list 105 deny tcp host 172.168.1.1 host 1.1.1.1 eq telnet
         access-list 105 deny tcp host 172.168.1.1 host 10.66.65.47 eq telnet
         !
         ! Police all other telnet and ftp connections to the auth-proxy router
         access-list 105 remark ** Police all other telnet/ftp attempts to Auth-Proxy Router **
         access-list 105 permit tcp any host 172.16.1.1 eq telnet
         access-list 105 permit tcp any host 1.1.1.1 eq telnet
         access-list 105 permit tcp any host 10.66.65.47 eq telnet
         access-list 105 permit tcp any host 172.16.1.1 eq ftp
         access-list 105 permit tcp any host 1.1.1.1 eq ftp
         access-list 105 permit tcp any host 10.66.65.47 eq ftp
         !
         ! Allow telnet and ftp auth-proxy for trusted network 169.160.160.0/24
         access-list 105 remark ** Allow Auth-Proxy sessions from trusted networks **
         access-list 105 deny tcp 169.160.160.0 0.0.0.255 any eq telnet
         access-list 105 deny tcp 169.160.160.0 0.0.0.255 any eq ftp
         !
         ! Allow telnet and ftp auth-proxy for trusted network back to 169.160.160.0/24
         access-list 105 remark ** Allow Auth-Proxy sessions to trusted networks **
         access-list 105 deny tcp host 172.168.1.1 169.160.160.0 0.0.0.255 
         !
         ! Allow TACACS+ from ACS server 10.66.79.229
         access-list 105 remark ** Ensure we can still communicate with TACACS+ Server **
         access-list 105 deny tcp host 10.66.79.229 gt 1023 host 10.66.65.47 eq 49
         access-list 105 deny tcp host 10.66.79.229 eq 49 host 10.66.65.47 gt 1023
         !
         ! Police all TCP based management traffic from un-trusted hosts
         ! Note: If BGP is configured it would need to be allowed before this access-list entry 
         access-list 105 remark ** Drop any other TCP connections **
         access-list 105 permit tcp any any
         !
         ! Do not police any other type of traffic going to the router
         access-list 105 remark ** Rest do not police **
         access-list 105 deny ip any any
         !
         class-map match-all only-allow-trusted-hosts
         match access-group 105
         !
         policy-map control-plane-policy
         ! Drop all traffic that matches the class "only-allow-trusted-hosts"
          class only-allow-trusted-hosts
           drop
         !
         control-plane
          service-policy input control-plane-policy

Note: CoPP is available only in IOS release trains 12.0S, 12.2S and 
      12.3T. Additional information on the configuration and use of 
      the CoPP feature can be found at the following URL: 
http://www.cisco.com/en/US/products/sw/iosswrel/ps1838/products_white_paper0...

Transit Access Control Lists
+---------------------------
Additional mitigation can be added by Transit Access Control Lists that
filter transit and edge traffic at network ingress points should be 
configured so that IP traffic is only allowed from legitimate, trusted
IP addresses. For more information on tACLs, refer to: 
http://www.cisco.com/warp/public/707/tacl.html

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

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

Status of This Notice: FINAL
======================

THIS ADVISORY IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY 
KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY.
YOUR USE OF THE INFORMATION ON THE ADVISORY OR MATERIALS LINKED FROM 
THE ADVISORY IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR
UPDATE THIS NOTICE AT ANY TIME.

A stand-alone copy or paraphrase of the text of this security advisory
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 will be posted on Cisco's worldwide website at:
http://www.cisco.com/warp/public/707/cisco-sa-20050907-auth_proxy.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-teams@first.org (includes CERT/CC)
    * 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 | 2005-September-07 | 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.h....
This includes instructions for press inquiries regarding Cisco security
notices. All Cisco security advisories are available at
http://www.cisco.com/go/psirt.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.1 (GNU/Linux)

iD8DBQFDIF/dezGozzK2tZARAtUgAKD9260CQGUcsbzUj1wpgxObhRCYhgCg0XLF
jNbXinrFA/4XXCgZZbvTntU=
=39rq
-----END PGP SIGNATURE-----

Cisco Security Advisory: Cisco IOS Firewall Authentication Proxy for FTP and Telnet Sessions Buffer Overflow

Cisco Systems Product Security Incident Response Team