Cisco Security Advisory: Cisco Secure Access Control Server for Windows User-Changeable Password Vulnerabilities
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Cisco Security Advisory: Cisco Secure Access Control Server for
Windows User-Changeable Password
Vulnerabilities
Advisory ID: cisco-sa-20080312-ucp
http://www.cisco.com/warp/public/707/cisco-sa-20080312-ucp.shtml
Revision 1.0
============
For Public Release 2008 March 12 1600 UTC (GMT)
Summary
=======
Two sets of vulnerabilities were discovered in the Cisco Secure
Access Control Server (ACS) for Windows User-Changeable Password
(UCP) application and reported to Cisco by Felix 'FX' Lindner,
Recurity Labs GmbH.
The first set of vulnerabilities address several buffer overflow
conditions in the UCP application that could result in remote
execution of arbitrary code on the host system where UCP is
installed.
The second set of vulnerabilities address cross-site scripting in the
UCP application pages.
Both sets of vulnerabilities could be remotely exploited, and do not
require valid user credentials.
Cisco has released a free software update for UCP that addresses
these vulnerabilities.
There are no workarounds that mitigate these vulnerabilities.
This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20080312-ucp.shtml
Affected Products
=================
UCP is the vulnerable application and can be installed to
inter-operate with:
* Cisco Secure ACS for Windows
* Cisco Secure ACS Solution Engine (Appliance)
NOTE: In Cisco Secure ACS for Windows, UCP may be installed on the
same or different host as the Cisco Secure ACS for Windows
application. In the Cisco Secure ACS Solution Engine (Appliance)
the UCP will be installed on a different host other than the
appliance.
UCP is not installed by default with ACS installations.
Vulnerable Products
+------------------
UCP versions prior to 4.2 are affected. Users can perform the
following steps to determine the version of UCP installed on a
system:
1. Log in to the system where UCP is installed
2. Open a Windows command prompt
3. Change the current working directory to the default directory of
the CGI scripts that was specified during installation of UCP.
The default installation directory is
"C:\Inetpub\Wwwroot\securecgi-bin". Within this directory execute
the command "CSuserCGI ver".
The output returned will indicate a CSuserCGI version. Any version
earlier than 4.2 is vulnerable. The following example shows a system
with UCP version 4.2 installed.
C:\> c:
C:\> cd c:\inetpub\Wwwroot\securecgi-bin
C:\Inetpub\Wwwroot\securecgi-bin>CSuserCGI ver
CSuserCGI 4.2, Copyright 2008 Cisco Systems Inc
Products Confirmed Not Vulnerable
+--------------------------------
Installations of Cisco Secure ACS for Windows or Cisco Secure ACS
Solution Engine without UCP installed, are not vulnerable.
Cisco Secure ACS for UNIX, does not support the UCP utility and is
not vulnerable.
No other Cisco products are currently known to be affected by these
vulnerabilities.
Details
=======
The UCP application enables end users to change their ACS passwords
with a web-based utility. When users need to change their own
passwords, they can access the UCP web page by using a supported web
browser, validate their existing credentials, and then change their
password via the utility.
For more information about the UCP application please see
http://www.cisco.com/en/US/docs/net_mgmt/cisco_secure_access_control_server_for_windows/4.2/installation/guide/user_passwords/ucp.html.
Several vulnerabilities exist within the UCP application.
* Multiple Buffer Overflow Vulnerabilities.
Multiple buffer overflows exist within the UCP CSuserCGI.exe
code. CSuserGCI.exe is the HTTP interface to the server.
This vulnerability is addressed by Cisco Bug ID CSCsl49180 and
has been assigned Common Vulnerabilities and Exposures (CVE)
identifier CVE-2008-0532
* Cross Site Scripting Vulnerabilities.
Cross-site scripting vulnerabilities exist within the UCP
CSuserCGI.exe code.
This vulnerability is addressed by Cisco Bug ID CSCsl49205 and
has been assigned Common Vulnerabilities and Exposures (CVE)
identifier CVE-2008-0533.
Vulnerability Scoring Details
=============================
Cisco has provided scores for the vulnerabilities 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 .
* CSCsl49180: Multiple Buffer Overflow Vulnerabilities.
CVSS Base Score - 10
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
* CSCsl49205: Cross Site Scripting Vulnerabilities.
CVSS Base Score - 4.3
Access Vector: Network
Access Complexity: Medium
Authentication: None
Confidentiality Impact: None
Integrity Impact: Partial
Availability Impact: None
CVSS Temporal Score - 3.6
Exploitability: Functional
Remediation Level: Official-Fix
Report Confidence: Confirmed
Impact
======
Successful exploitation of the buffer overflow vulnerabilities may
result in the execution of arbitrary code on the system the UCP
application is installed.
Successful exploitation of the cross-site scripting vulnerabilities
may result in the embedding of malicious code and/or scripts within a
UCP URL.
The malicious code is likely to be a script that is embedded in the
URL of a link. The malicious code may also be stored on the
vulnerable server or a malicious website. An attacker could try to
convince an unsuspecting user to follow a malicious link to a
vulnerable UCP application server that injects (reflects) the
malicious code back to the user's browser.
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.
UCP Version 4.2 contains the fixes for the listed vulnerabilities.
UCP Version 4.2 can be downloaded from the following location:
http://www.cisco.com/cgi-bin/Software/Tablebuild/doftp.pl?ftpfile=cisco/crypto/3DES/ciscosecure/special/acs/macgyver/UCP_4.2.0.124-K9.zip&app=Tablebuild&status=showC2A
Note: UCP Version 4.2 works with all 4.x version of Cisco Secure
ACS for Windows and Cisco Secure ACS Solution Engine. UCP
version 4.2 is not compatible with 3.x ACS installations.
No fixed UCP version exists for 3.x ACS installations.
Workarounds
===========
There are no workarounds for these vulnerabilities. Cisco recommends
upgrading to the fixed version of UCP.
For additional information on cross-site scripting attacks and the
methods used to exploit these vulnerabilities, please refer to the
Cisco Applied Mitigation Bulletin "Understanding Cross-Site Scripting
(XSS) Threat Vectors", which is available at the following link:
http://www.cisco.com/warp/public/707/cisco-amb-20060922-understanding-xss.shtml
Obtaining Fixed Software
========================
Cisco has released free software updates that address these
vulnerabilities. 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.
We would like to thank Felix 'FX' Lindner, Recurity Labs GmbH for
reporting this issue to us. We greatly appreciate the opportunity to
work with researchers on security vulnerabilities, and welcome the
opportunity to review and assist with security vulnerability reports
against Cisco products.
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-20080312-ucp.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 1.0 | 2008-Mar-12 | 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.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (Darwin)
iD8DBQFH1/jr86n/Gc8U/uARAs8RAJ9CjRFqB8rwYtrpXTVIol2QW7jG9wCeMT/F
u8p4qv+1c9/UQTmBx5TR7O4=
=U667
-----END PGP SIGNATURE-----