March 2005
Cisco - Two Security Advisories: 1. Cisco VPN 3000 Concentrator Vulnerable to Crafted SSL attack - 2. Cisco IPSec Malformed IKE Packet Vulnerability (Revision 2.0)
ID: 00260
Ref: 239/05
Date: 31 March 2005:15:52:43
Version: 1
Title: Cisco - Two Security Advisories: 1. Cisco VPN 3000 Concentrator Vulnerable to Crafted SSL attack - 2. Cisco IPSec Malformed IKE Packet Vulnerability (Revision 2.0)
Abstract:
Vendors affected: Cisco
Operating systems affected: Cisco
Applications affected: Cisco
Title
=====
Cisco - Two Security Advisories:
1. Cisco VPN 3000 Concentrator Vulnerable to Crafted SSL attack
2. Cisco IPSec Malformed IKE Packet Vulnerability (Revision 2.0)
Detail
======
Security Advisory summaries:
1. A malicious user may be able to send a crafted attack via SSL (Secure
Sockets Layer) to the concentrators which may cause the device to reload,
and/or drop user connections. Repeated exploitation will create a
sustained DoS (denial of service).
2. A malformed Internet Key Exchange (IKE) packet may cause the Cisco
Catalyst 6500 Series Switch or the Cisco 7600 Series Internet Router to
reload. Only devices running Cisco IOS software with Crypto support are
affected.
Security Advisory content follows:
1.
-----BEGIN PGP SIGNED MESSAGE-----
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=================================================================
Cisco Security Advisory: Cisco VPN 3000 Concentrator Vulnerable to Crafted SSL
attack
=================================================================
Revision 1.0
For Public Release 2005 March 30 1600 UTC (GMT)
+------------------------------------------------------------------------------
Please provide your feedback on this document.
+------------------------------------------------------------------------------
Contents
========
Summary
Affected Products
Details
Impact
Software Versions and Fixes
Workarounds
Exploitation and Public Announcements
Status of This Notice: FINAL
Distribution
Revision History
Cisco Security Procedures
+------------------------------------------------------------------------------
Summary
=======
The Cisco VPN 3000 series concentrators are a family of purpose-built, remote
access Virtual Private Network (VPN) platforms for data encryption and
authentication.
A malicious user may be able to send a crafted attack via SSL (Secure Sockets
Layer) to the concentrators which may cause the device to reload, and/or drop
user connections.
Repeated exploitation will create a sustained DoS (denial of service).
Workarounds are available to mitigate this vulnerability.
Cisco has made free software available to address this vulnerability for all
affected customers.
This vulnerability is documented in the Cisco Bug Toolkit as Bug ID CSCeg11424
( registered customers only)
This advisory is available at
http://www.cisco.com/warp/public/707/cisco-sa-20050330-vpn3k.shtml
Affected Products
=================
Vulnerable Products
+------------------
Cisco VPN 3000 series concentrators running software 4.1.7.A and earlier are
affected by this vulnerability.
This series includes models 3005, 3015, 3020, 3030, 3060, 3080 and the Cisco
VPN 3002 Hardware Client.
Products Confirmed Not Vulnerable
+--------------------------------
The following products are confirmed not vulnerable:
* Cisco IPSec VPN Services Module (VPNSM)
* Cisco VPN 5000 Concentrators
* Cisco PIX Firewalls
* Any Cisco device that runs Cisco's Internetwork Operating System (IOS)
* Any Cisco device that runs Cisco's Catalyst Operating System (CatOS)
No other Cisco products are currently known to contain this vulnerability.
Details
=======
Secure Sockets Layer (SSL) is a protocol used to encrypt the data transferred
over a TCP session. SSL in Cisco products is mainly used by the HyperText
Transfer Protocol Secure (HTTPS) web service for which the default TCP port is
443. Due to this vulnerability, a malicious user may send crafted HTTPS packets
which may result in a reload of the affected device or and/or user connections
being dropped.
The affected products are only vulnerable if they have the HTTPS service
enabled and the access to the service is not limited to trusted hosts or
network management workstations. By default, HTTPS is not enabled on VPN 3000
devices, and must be manually enabled. Affected devices are not vulnerable to
transit traffic, only traffic that is destined to them may exploit this
vulnerability.
To check if the HTTPS service is enabled, one can do the following:
1. Check the configuration on the device to verify the status of the HTTPS
service.
2. Try to connect to the device using a standard web browser that supports SSL
using a URL similar to https://ip_address_of_device/.
No authentication is required to exploit this vulnerability.
This vulnerability is documented in the Cisco Bug Toolkit as Bug ID CSCeg11424
( registered customers only)
Impact
======
Successful exploitation of this vulnerability may result in a reload of the
affected device or and/or user connections being dropped. Repeated exploitation
of this vulnerability could result in a sustained Denial of Service.
Software Versions and Fixes
===========================
Cisco VPN 3000 series users can upgrade to version 4.1.7.B or later software to
resolve this vulnerability.
When considering software upgrades, please also consult
http://www.cisco.com/warp/public/707/advisory.html 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.
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
===========
Disable HTTPS
+------------
Disabling HTTPS will effectively mitigate this vulnerability, provided the
concentrator is used only for IPSEC, PPTP or L2TP over IPsec VPN connections.
If the concentrator is configured for WebVPN connectivity, disabling HTTPS will
also render WebVPN inoperable.
For details on how to disable HTTPS, please reference
www.cisco.com/en/US/products/hw/vpndevc/ps2284/
products_configuration_guide_chapter09186a00803ee1e4.html#wp1309633.
Transit ACLs
+-----------
SSL to the VPN3000 could be blocked as part of a Transit ACL on screening
routers, switches and firewalls controlling all access to the trusted network.
Transit 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 entitled "Transit
Access Control Lists: Filtering at Your Edge" presents guidelines and
recommended deployment techniques for transit ACLs:
http://www.cisco.com/warp/public/707/tacl.html.
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.
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 during internal Cisco security review.
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://cisco.com/warp/public/707/cisco-sa-20050330-vpn3k.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 | 2005-March-30 | Initial |
| 1.0 | | 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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2.
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Hash: SHA1
Cisco Security Advisory: Cisco IPSec Malformed IKE Packet Vulnerability
Revision 2.0
Last Updated 2005 March 30 at 1600 UTC (GMT)
For Public Release 2004 April 8 at 1600 UTC (GMT)
- -----------------------------------------------------------------------
Contents
========
Summary
Affected Products
Details
Impact
Software Versions and Fixes
Obtaining Fixed Software
Workarounds
Exploitation and Public Announcements
Status of This Notice: FINAL
Distribution
Revision History
Cisco Security Procedures
- -----------------------------------------------------------------------
Summary
=======
A malformed Internet Key Exchange (IKE) packet may cause the Cisco
Catalyst 6500 Series Switch or the Cisco 7600 Series Internet Router to
reload. Only devices running Cisco IOS software with Crypto support are
affected.
This vulnerability is documented as Cisco bug ID CSCed30113. There are
workarounds available to mitigate the effects of this vulnerability.
Cisco has made free software available to address this vulnerability
for all affected customers.
The title of this advisory has been updated from "Cisco IPSec VPN
Services Module Malformed IKE Packet Vulnerability" to the current
title due to a change in the products affected no longer being limited
to those devices with a VPN Services Module installed.
This advisory will be posted at
http://www.cisco.com/warp/public/707/cisco-sa-20040408-vpnsm.shtml
Affected Products
=================
Vulnerable Products
+------------------
The vulnerability is only present if a Crypto feature set is being
used. Customers can verify if they are running a Crypto feature set via
the show version command:
Router#show version
Cisco Internetwork Operating System Software
IOS (tm) c6sup2_rp Software (c6sup2_rp-PK9S-M), Version 12.2(18)SXD3, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Thu 09-Dec-04 19:35 by pwade
Image text-base: 0x4002100C, data-base: 0x422E8000
Software that contains the 'K9' designation, as in the following line,
includes the Crypto feature set:
IOS (tm) c6sup2_rp Software (c6sup2_rp-PK9S-M), Version 12.2(18)SXD3, RELEASE SOFTWARE (fc1)
All Cisco Catalyst 6500 Series Switch and the Cisco 7600 Series
Internet Router hardware running the following Cisco IOS releases are
affected by this vulnerability.
+----------------------------------------+
| Release | Affected Releases |
| Train | |
|------------+---------------------------|
| 12.2SXA | earlier than 12.2(17b)SXA |
|------------+---------------------------|
| 12.2SXB | earlier than 12.2(17d)SXB |
|------------+---------------------------|
| 12.2SX | 12.2(17a)SX through 12.2 |
| | (17a)SX4 |
|------------+---------------------------|
| 12.2SY | earlier than 12.2(14)SY3 |
+----------------------------------------+
Products Confirmed Not Vulnerable
=================================
Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Internet
Routers running Cisco IOS release train 12.1E are not affected by this
vulnerability.
To determine your software revision, type show version at the command
line prompt.
No other Cisco products are currently known to be affected by this
vulnerability.
Details
=======
A malformed IKE packet may cause an affected device to reload.
This vulnerability could be used to conduct a Denial of Service (DoS)
attack against a vulnerable device. This vulnerability is known to only
exist in the modified IKE code which was incorporated in the 12.2SXA,
12.2SXB, 12.2SX and 12.2SY Cisco IOS software release trains.
Cisco IOS devices with Crypto support will process IKE messages by
default. More information can be found here:
http://cco.cisco.com//en/US/products/sw/iosswrel/ps5187/products_command_reference_chapter09186a008017cf18.html#wp1071565
The Internetworking Terms and Cisco Systems Acronyms online guides can
be found at http://www.cisco.com/univercd/cc/td/doc/cisintwk/.
This vulnerability is documented in the Cisco Bug Toolkit as Bug ID
CSCed30113
Impact
======
Successful exploitation of this vulnerability could result in a reload
of the device. Repeated exploitation could result in a sustained DoS
attack.
Software Versions and Fixes
===========================
This vulnerability has been fixed in the following Cisco IOS releases
for the Cisco Catalyst 6500 Series Switch and the Cisco 7600 Series
Internet Router hardware:
+----------------------------------------+
| Release | Fixed Releases |
| Train | |
|------------+---------------------------|
| 12.2SXA | 12.2(17b)SXA and later |
|------------+---------------------------|
| 12.2SXB | 12.2(17d)SXB and later |
|------------+---------------------------|
| 12.2SX | Migrate to 12.2(17d)SXB |
| | or later |
|------------+---------------------------|
| 12.2SY | 12.2(14)SY3 and later |
+----------------------------------------+
Please refer to these documents for more information:
* 12.2(17b)SXA Release Notes:
http://www.cisco.com/en/US/products/sw/iosswrel/ps5014/prod_bulletin09186a00801df1dd.html
* 12.2(17d)SXB Release Notes:
http://www.cisco.com/en/US/products/sw/iosswrel/ps5012/prod_bulletin09186a00802078b5.html
* 12.2(14)SY3 Release Notes:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/relnotes/ol_3975.htm
When considering software upgrades, please also consult
http://www.cisco.com/warp/public/707/advisory.html 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.
Obtaining Fixed Software
========================
Cisco is offering free software upgrades to address this vulnerability
for all affected customers.
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/tacpage/library/12.2/index.shtml.
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.
Customers that do not require IPSec functionality on their devices can
use the command 'no crypto isakmp enable' in configuration mode to
disable processing of IPSec and eliminate their exposure.
As a possible mitigation, access-lists could be applied on the affected
IOS platforms to limit the source IP addresses permitted to establish
IPSec sessions to the device.
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 reported to Cisco PSIRT by a customer.
Status of This Notice: FINAL
============================
This is a final advisory. Although Cisco cannot guarantee the accuracy
of all statements in this advisory, all of the facts have been checked
to the best of our ability. Cisco does not anticipate issuing updated
versions of this advisory unless there is some material change in the
facts. Should there be a significant change in the facts, Cisco may
update this advisory.
Note: 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-20040408-vpnsm.shtml
In addition to worldwide web posting, a text version of this notice is
clear-signed with the Cisco PSIRT PGP key having the fingerprint 8C82
5207 0CA9 ED40 1DD2 EE2A 7B31 A8CF 32B6 B590 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.netsys.com
* comp.dcom.sys.cisco@newsgate.cisco.com
* Various internal Cisco mailing lists
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
================
+-----------------------------------------+
| | | Updated the |
| | | advisory to |
| | | reflect |
| | | devices |
| | | without the |
| | | VPNSM may |
| | | be |
| | | affected. |
| | | Added 12.2 |
| | | (17d)SX as |
| Revision | 2005-March-30 | an affected |
| 2.0 | | release |
| | | train. |
| | | Added |
| | | information |
| | | for |
| | | determining |
| | | the |
| | | presence of |
| | | the crypto |
| | | feature |
| | | set. |
|----------+----------------+-------------|
| | | Updated the |
| | | 12.2(14) |
| | | SY03 |
| | | Release |
| Revision | 2005-January-4 | Notes URL |
| 1.2 | | in the |
| | | Software |
| | | Fixes and |
| | | Versions |
| | | section. |
|----------+----------------+-------------|
| | | Removed |
| | | 12.2ZA as a |
| Revision | | vulnerable |
| 1.1 | 2004-April-8 | Cisco IOS |
| | | software |
| | | release |
| | | train. |
|----------+----------------+-------------|
| Revision | | Initial |
| 1.0 | 2004-April-8 | 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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