Re: Cisco PIX security advisory - upgrade to 6.3.5 ASAP



More than just PIX!

Contents of link previously posted:

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Multiple Vulnerabilities Found by PROTOS IPSec Test Suite

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Multiple Vulnerabilities Found by PROTOS IPSec Test Suite





Document ID: 68158


Advisory ID: 68158
http://www.cisco.com/warp/public/707/cisco-sa-20051114-ipsec.shtml
Revision 1.1
Last Updated 2005 November 14 2100 GMT (UTC)
For Public Release 2005 November 14 1100 GMT (UTC)

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Contents
Summary
Affected Products
Details
Impact
Software Versions and Fixes
Workarounds
Obtaining Fixed Software
Exploitation and Public Announcements
Status of This Notice: FINAL
Distribution
Revision History
Cisco Security Procedures


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Summary
Multiple Cisco products contain vulnerabilities in the processing of IPSec
IKE (Internet Key Exchange) messages. These vulnerabilities were identified
by the University of Oulu Secure Programming Group (OUSPG) "PROTOS" Test
Suite for IPSec and can be repeatedly exploited to produce a denial of
service.

Cisco has made free software available to address this vulnerability for
affected customers. 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.

This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20051114-ipsec.shtml.

Affected Products
Vulnerable Products
Cisco devices running affected versions of software and configured for IKE
are vulnerable. This vulnerability is not dependent on a specific hardware
configuration. For example, the Cisco VPNSM or VPN SPA are not required for
the device to be vulnerable.

Cisco IOS versions based on 12.2SXD, 12.3T, 12.4 and 12.4T

Cisco PIX Firewall versions up to but not including 6.3(5)

Cisco PIX Firewall/ASA versions up to but not including 7.0.1.4

Cisco Firewall Services Module (FWSM) versions up to but not including
2.3(3)

Cisco VPN 3000 Series Concentrators versions up to but not including 4.1(7)H
and 4.7(2)B

Cisco MDS Series SanOS versions up to but not including 2.1(2)

To determine the software running on a Cisco IOS 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-JO3S-M.

Router# show version
Cisco Internetwork Operating System Software
IOS (tm) 7200 Software (C7200-JO3S-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/en/US/products/sw/iosswrel/ps1828/products_white_paper09186a008018305e.shtml.

Only Cisco IOS images that contain the Crypto Feature Set contain the
vulnerable IPSec code. Customers that are not running an IOS image with
crypto support are not exposed to this vulnerability.

Cisco IOS feature set naming indicates that IOS images with crypto support
will have 'K8' or 'K9' in the feature designator field.

For example, the image in the example above, C7200-JO3S-M, does not contain
'K8' or 'K9.' This indicates that this image does not support crypto, and is
therefore not vulnerable to the issues described in this Security Advisory.

The following output was taken from a device that is running an IOS image
with crypto support:

Cisco Internetwork Operating System Software
IOS (tm) c6sup2_rp Software (c6sup2_rp-PK9S-M), Version 12.2(18)SXD5,
RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2005 by cisco Systems, Inc.
Compiled Fri 13-May-05 21:12 by ssearchSince the feature set designator
(PK9S) contains 'K9', we can quickly determine that this feature set
contains crypto support.

Products Confirmed Not Vulnerable
No other IOS trains are known to be affected.

Cisco IOS XR is not affected.

No other Cisco products are currently known to be affected by these
vulnerabilities.

Details
IP Security, or IPSec, is a set of protocols standardized by the IETF to
support encrypted and/or authenticated transmission of IP packets. IPSec is
a protocol commonly used in Virtual Private Networks (VPNs).

The Internet Key Exchange (IKE) protocol is used to negotiate keying
material for IPSec Security Associations (SAs) and provides authentication
of peers.

For more complete information on IPSec, consult IETF Request For Comments
(RFCs) 2401:

http://www.ietf.org/rfc/rfc2401.txt

For more complete information on IKE, consult IETF Request For Comments
(RFCs) 2408 and 2409:

http://www.ietf.org/rfc/rfc2408.txt

http://www.ietf.org/rfc/rfc2409.txt

IPSec is used in two general cases.

The first case is LAN-to-LAN VPN operation in which two devices negotiate an
IPSec connection between them for the purposes of connecting two remote LANs
via an IPSec tunnel. In this case the devices negotiating the IPSec
connection generally have static IP addresses, and the IPSec tunnel is up as
long as there is traffic that needs to traverse the tunnel.

The second case is a Remote Access (RA) VPN which is typically used to allow
remote clients a connection to a secure network or service. A common example
of this is a user connecting to a corporate network while away from the
office. In this scenario, the remote user could be connecting from anywhere,
and their IP address is not static, but rather dynamically assigned via the
transport provider.

IKE is not a requirement for the establishment of IPSec connections.
Depending on your requirements and the devices involved, it may be possible
to statically configure the SA information and disable IKE. This type of
configuration may not be possible in the case of RA VPNs due to the user's
IP address being unknown prior to the establishment of the IPSec connection.
See the Workarounds Section for more information.

The PROTOS test suite for IPSec is designed to test the design limits of
IPSec implementations by sending malformed IKE messages to the target
device.

When receiving certain malformed packets, vulnerable Cisco devices may
reset, causing a temporary Denial of Service (DoS).

The vulnerabilities identified can be easily and repeatedly reproduced with
the use of the OUSPG "PROTOS" Test Suite for IKE. This suite is designed to
test the design limits of implementations that process IKE messages.

Additional Details for Cisco IOS
The vulnerabilities addressed by this Advisory were introduced in IOS
version 12.3(11)T and are present in versions of 12.3T, 12.4, 12.4T and
12.2SXD.

Prior to IOS version 12.3(8)T, IKE was enabled by default, with no crypto
configuration needed for the IOS device to process IKE messages.

12.2SXD versions of Cisco IOS have IKE enabled by default. To ensure that
IKE processing is disabled, enter the global configuration command no crypto
isakmp enable.

As of IOS version 12.3(8)T (which includes all 12.4-based versions), crypto
configuration is required to enable IKE message processing.

In order for an IOS device to process IKE packets, a crypto map must be
configured and applied to an interface.

Additional Details for Cisco PIX
The Cisco PIX does not enable IKE processing by default in any versions of
software.

For Cisco PIX versions prior to 7.0, use the following to determine if IKE
message processing is enabled:

show isakmp enable
The following example shows the output when IKE is enabled on the outside
interface:

pixfirewall(config)# show isakmp enable
isakmp enable outsideThe following example shows the output when IKE is not
enabled on any interface:

pixfirewall(config)# show isakmp
pixfirewall(config)#For Cisco PIX/ASA versions 7.0 and later, IKE is enabled
only if the following command is in the device configuration:

isakmp enable
Cisco Bug IDs
Below are the Cisco bug IDs and their corresponding product(s):

Cisco IOS versions based on 12.2SX, 12.3T, 12.4 and 12.4T - CSCed94829 (
registered customers only)

Cisco PIX Firewall versions up to but not including 6.3(5) - CSCei14171 (
registered customers only)

Cisco PIX Firewall/ASA versions up to but not including 7.0.1.4 - CSCei15053
( registered customers only)

Cisco Firewall Services Module (FWSM) versions up to but not including
2.3(3) - CSCei19275 ( registered customers only)

Cisco VPN 3000 Series Concentrators versions up to but not including 4.1(7)H
and 4.7(2)B - CSCsb15296 ( registered customers only)

Cisco MDS Series SanOS versions up to but not including 2.1(2) - CSCei46258
( registered customers only)

Impact
Successful exploitation of the vulnerability on the Cisco MDS Series may
result in the restart of the IKE process. All other Cisco MDS device
operations will continue normally.

Successful exploitation of the vulnerabilities on all other Cisco devices
may result in the restart of the device. The device will return to normal
operation without any intervention required.

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.

Non-IOS Products
Affected Product
Vulnerable Version
Fixed Version

Cisco PIX running pre-7.0 code
Up to, but not including, 6.3(5)
6.3(5) or later

Cisco PIX/ASA running 7.0 or later code
Up to, but not including 7.0.1.4
7.0.1.4 or later

Cisco FWSM for Catalyst 6500 or 7600
Up to, but not including, 2.3(3)
2.3(3) or later

Cisco VPN3000 Concentrators running pre 4.7 code
4.1(7)H
4.1(7)H

Cisco VPN3000 Concentrators running 4.7 code
Up to, but not including, 4.7(2)B
4.7(2)B or later

Cisco MDS devices
Up to, but not including, 2.1(2)
2.1(2) or later



Cisco IOS
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

For Cisco IOS, the vulnerabilities were introduced with 12.3(11)T and
12.2(18)SXD. Previous versions of Cisco IOS are not affected.

Major Release
Availability of Repaired Releases

Affected 12.2-Based Release
Rebuild
Maintenance

12.2SXD
12.2(18)SXD7; available End of Dec, 2005

Migrate to 12.2(18)SXE

Affected 12.3-Based Release
Rebuild
Maintenance

12.3T
12.3(11)T9; available 12-Dec-05

12.3(14)T5

12.3YF
Vulnerable; contact TAC

12.3YK
Vulnerable; migrate to 12.4(4)T

12.3YM
12.3(14)YM4

12.3YQ
12.3(14)YQ4; available TBD

12.3YS
Vulnerable; contact TAC

12.3YT
Vulnerable; migrate to 12.4(4)T

12.3YU
Vulnerable; contact TAC

12.3YX
Vulnerable; contact TAC

Affected 12.4-Based Release
Rebuild
Maintenance

12.4
12.4(1c); available 14-Nov-05

12.4(3b); available 15-Nov-05
12.4(5)

12.4T
12.4(2)T2

12.4(4)T

12.4XA
Vulnerable; contact TAC

12.4XB
12.4(2)XB; available TBD



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.

For customers that use IPSec, but do not require IKE for connection
establishment, IPSec connection information may be able to be entered
manually, and IKE can be disabled, eliminating the exposure.

Note: Due to the potential complexity of configuring IPSec information, this
is likely not a viable alternative for most customers, but is mentioned here
for completeness. Please consult your product documentation for further
information on static IPSec configuration.

Restricting IKE Messages
It is possible to mitigate the effects of this vulnerability by restricting
the devices that can send IKE traffic to your IPSec devices. Due to the
potential for IKE traffic to come from a spoofed source address, a
combination of Access Control Lists (ACLs) and anti-spoofing mechanisms will
be most effective.

Anti-spoofing
The Unicast Reverse Path Forwarding (Unicast RPF) feature helps to mitigate
problems that are caused by spoofed IP source addresses. It is available on
Cisco routers and firewalls. For further details, please refer to:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fsecur_c/fothersf/scfrpf.htm

By enabling Unicast Reverse Path Forwarding (uRPF), all spoofed packets will
be dropped at the first device. To enable uRPF, use the following commands.

router(config)# ip cef
router(config)# interface <interface #>
router(config-if)# ip verify unicast reverse-path
Infrastructure Access Control Lists
Although it is often difficult to block traffic transiting your network, it
is possible to identify traffic which should never be allowed to target your
infrastructure devices and block that traffic at the border of your network.
Infrastructure ACLs are considered a network security best practice and
should be considered as a long-term addition to good network security as
well as a workaround for this specific vulnerability. The white paper
"Protecting Your Core: Infrastructure Protection Access Control Lists"
presents guidelines and recommended deployment techniques for infrastructure
protection ACLs: http://www.cisco.com/warp/public/707/iacl.html.

Obtaining Fixed Software
Cisco has made free software available to address this vulnerability for
affected customers. 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/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.

Do not contact either "psirt@xxxxxxxxx" or "security-alert@xxxxxxxxx" 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 agreement 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 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@xxxxxxxxx

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.

Refer to 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.

Exploitation and Public Announcements
The OUSPG Test Suite for IPSec can be used to trigger these vulnerabilities.

These vulnerabilities were discovered in cooperation with CERT-FI and NISCC.
For their release information, please see
http://www.niscc.gov.uk/niscc/vulnAdv-en.html.

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-20051114-ipsec.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@xxxxxxxxx

first-teams@xxxxxxxxx

bugtraq@xxxxxxxxxxxxxxxxx

vulnwatch@xxxxxxxxxxxxx

cisco@xxxxxxxxxxxxxxxxx

cisco-nsp@xxxxxxxxxxxxxxx

full-disclosure@xxxxxxxxxxxxxxxxx

comp.dcom.sys.cisco@xxxxxxxxxxxxxxxxxx

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 1.1
14-November-2005
Updated Non-IOS Products table. Updated command output in the Additional
Details for Cisco PIX section. Updated Additional Details for Cisco IOS
section.

Revision 1.0
14-November-2005
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.



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Updated: Nov 14, 2005 Document ID: 68158









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