Advisory ID: cisco-sa-20070103-CleanAccess
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20070103-CleanAccess
Revision 1.0
For Public Release 2007 January 3 16:00 UTC (GMT)
Contents
Summary
Affected Products
Details
Vulnerability Scoring 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
Summary
Cisco Clean Access (CCA) is a software solution that can automatically detect, isolate, and clean infected or vulnerable devices that attempt to access your network. It consists of Cisco Clean Access Manager (CAM) and Cisco Clean Access Server (CAS) devices that work in tandem.
Cisco Clean Access is affected by the following vulnerabilities:
- Unchangeable shared secret
- Readable snapshot files
Affected Products
Vulnerable Products
The following software releases are vulnerable.
Unchangeable Shared Secret
- CCA releases 3.6.x - 3.6.4.2
- CCA releases 4.0.x - 4.0.3.2
Readable Snapshots
- CCA releases 3.5.x - 3.5.9
- CCA releases 3.6.x - 3.6.1.1
Products Confirmed Not Vulnerable
No other Cisco products are known to be affected by the vulnerabilities described in this Advisory.
Details
Unchangeable Shared Secret
In order for Cisco Clean Access Manager (CAM) to authenticate to a Cisco Clean Access Server (CAS), both CAM and CAS must have the same shared secret. The shared secret is configured during the initial CAM and CAS setup. Due to this vulnerability the shared secret can not be properly set nor be changed, and it will be the same across all affected devices. In order to exploit this vulnerability the adversary must be able to establish a TCP connection to CAS.
This vulnerability is documented in Cisco Bug ID CSCsg24153 ( registered customers only) .
Readable Snapshots
Manual backups of the database ('snapshots') taken on CAM are susceptible to brute force download attacks. A malicious user can guess the file name and download it without authentication. The file itself is not encrypted or otherwise protected.
This vulnerability is documented in Cisco Bug ID CSCsd48626 ( registered customers only) .
Vulnerability Scoring Details
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 .
|
CSCsg24153 - Unchangeable shared secret ( registered customers only) |
||||||
|---|---|---|---|---|---|---|
|
CVSS Base Score - 8 |
||||||
|
Access Vector |
Access Complexity |
Authentication |
Confidentiality Impact |
Integrity Impact |
Availability Impact |
Impact Bias |
|
Remote |
High |
Not Required |
Complete |
Complete |
Complete |
Normal |
|
CVSS Temporal Score - 6.3 |
||||||
|
Exploitability |
Remediation Level |
Report Confidence |
||||
|
Proof of Concept |
Official Fix |
Confirmed |
||||
|
CSCsd48626 - Readable snapshot files ( registered customers only) |
||||||
|---|---|---|---|---|---|---|
|
CVSS Base Score - 10 |
||||||
|
Access Vector |
Access Complexity |
Authentication |
Confidentiality Impact |
Integrity Impact |
Availability Impact |
Impact Bias |
|
Remote |
Low |
Not Required |
Complete |
Complete |
Complete |
Normal |
|
CVSS Temporal Score - 8.3 |
||||||
|
Exploitability |
Remediation Level |
Report Confidence |
||||
|
Functional |
Official Fix |
Confirmed |
||||
Impact
Unchangeable Shared Secret
Successful exploitation of the vulnerability may enable a malicious user to effectively take administrative control of a CAS. After that, every aspect of CAS can be changed including its configuration and setup.
Readable Snapshots
The snapshot contains sensitive information that can aide in the attempts, or be used to compromise the CAM. Among other things, the snapshot can contain passwords in cleartext. Starting with the release 3.6.0, passwords are no longer stored in cleartext in the snapshot files.
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.
The following CCA software releases contain the fixes.
Unchangeable Shared Secret
The following software releases contain the fix for this vulnerability: 3.6.4.3, 4.0.4 and 4.1.0. All subsequent releases will contain the fix.
The alternative is to install the patch Patch-CSCsg24153.tar.gz which is available at http://www.cisco.com/pcgi-bin/tablebuild.pl/cca-patches. This patch provides the fix only for the Unchangeable Shared Secret issue and does not addreses any other vulnerability.
Readable Snapshots
The following software releases contain the fix for this vulnerability: 3.5.10 and 3.6.2. All subsequent releases will contain the fix.
Workarounds
There are no workarounds for these vulnerabilities.
Possible mitigation of threat posed by readable snapshot files is to remove them from the device shortly after they were created. If the snapshot file needs to be preserved then it can be moved to a different computer or archived on a secondary storage. Alternately, the snapshot file can be deleted from the device.
Obtaining Fixed Software
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/docs/general/warranty/English/EU1KEN_.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@cisco.com or security-alert@cisco.com for software upgrades
Customers with Service Contracts
Customers Using Third-Party Support Organizations
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@cisco.com
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/en/US/support/tsd_cisco_worldwide_contacts.html 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.
The readable snapshot issue was reported to Cisco by Chris Hartley from Ohio State University. The unchangeable shared secret was discovered while working on a customer's case and is unrelated to the Mr. Hartley's report.
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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20070103-CleanAccess
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
- 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
|
1.0 |
2007-Jan-03 |
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.
