Cisco Security Advisory: Cisco Network Admission Control Shared Secret Vulnerability
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Cisco Security Advisory: Cisco Network Admission Control Shared Secret
Vulnerability
Advisory ID: cisco-sa-20080416-nac
http://www.cisco.com/warp/public/707/cisco-sa-20080416-nac.shtml
Revision 1.0
For Public Release 2008 April 16 1600 UTC (GMT)
Summary
=======
A vulnerability exists in the Cisco Network Admission Control (NAC)
Appliance that can allow an attacker to obtain the shared secret that
is used between the Cisco Clean Access Server (CAS) and the Cisco Clean
Access Manager (CAM).
Cisco has released free software updates that address this
vulnerability.
This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20080416-nac.shtml.
Affected Products
=================
Vulnerable Products
+------------------
The following table lists all Cisco NAC Appliance software versions
affected by this vulnerability.
+---------------------------------------+
| NAC Software | Vulnerable Versions |
| Release | |
|--------------+------------------------|
| 3.5.x | All 3.5.x versions |
|--------------+------------------------|
| 3.6.x | All 3.6.x versions |
| | prior to 3.6.4.4 |
|--------------+------------------------|
| 4.0.x | All 4.0.x versions |
| | prior to 4.0.6 |
|--------------+------------------------|
| 4.1.x | All 4.1.x versions |
| | prior to 4.1.2 |
+---------------------------------------+
Products Confirmed Not Vulnerable
+--------------------------------
Cisco NAC Appliance software versions 3.6.4.4 and later in the 3.6.x
train; 4.0.6 and later in the 4.0.x train; and 4.1.2 and later in the
4.1.x train are not vulnerable. No other Cisco products are currently
known to be affected by this vulnerability.
Details
=======
The Cisco NAC Appliance solution allows network administrators to
authenticate, authorize, evaluate, and remediate wired, wireless,
and remote users and their machines prior to allowing users onto the
network. The solution identifies whether machines are compliant with
security policies and repairs vulnerabilities before permitting access
to the network.
A vulnerability exists in the Cisco NAC Appliance that can allow an
attacker to obtain the shared secret used by the CAS and the CAM from
error logs that are transmitted over the network. Obtaining this
information could enable an attacker to gain complete control of the CAS
remotely over the network.
This vulnerability is documented in Cisco Bug ID CSCsj33976 and has
been assigned Common Vulnerabilities and Exposures (CVE) identifier
CVE-2008-1155.
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.
* NAC Appliance Shared Secret Vulnerability (CSCsj33976)
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 of the vulnerability could allow an attacker to
take complete control of the CAS remotely over the network.
Software Versions and Fixes
===========================
Each row of the following software table (below) describes the earliest
possible releases that contain the fix for this vulnerability. These are
shown in the "First Fixed Release" column. 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).
+---------------------------------------+
| Affected Releases | First Fixed |
| | Releases |
|----------------------+----------------|
| NAC Appliance | Vulnerable - |
| software version | Contact TAC |
| 3.5.x | |
|----------------------+----------------|
| NAC Appliance | |
| software version | 3.6.4.4 |
| 3.6.x | |
|----------------------+----------------|
| NAC Appliance | |
| software version | 4.0.6 |
| 4.0.x | |
|----------------------+----------------|
| NAC Appliance | |
| software version | 4.1.2 |
| 4.1.x | |
+---------------------------------------+
You can download NAC Appliance software from
http://www.cisco.com/public/sw-center/ciscosecure/cleanaccess.shtml.
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.
Workarounds
===========
There are no workarounds for this vulnerability.
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/products/prod_warranties_item09186a008088e31f.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@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 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@xxxxxxxxx
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/warp/public/687/Directory/DirTAC.shtml
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 issue was discovered by Cisco through internal testing.
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-20080416-nac.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 | 2008-April-16 | Initial public |
| 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.
+----------------------------------------------------------------------
All contents are Copyright (C) 2006-2008 Cisco Systems, Inc. All rights
reserved.
+----------------------------------------------------------------------
Updated: Apr 16, 2008 Document ID: 100782
+----------------------------------------------------------------------
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