Products & Services
Support

Product Categories


Popular Downloads


Manage Software

How to Buy

For Home

Linksys Products Store
Linksys is now part of Belkin
Products for everyone

All Ordering Options

Training & Events Partners
Guest

Vulnerability Alert

Cisco Secure Access Control System TACACS+ Authentication Bypass Vulnerability

 
Threat Type:CWE-287: Authentication Issues
IntelliShield ID:27307
Version:1
First Published:2012 November 07 11:15 GMT
Last Published:2012 November 07 16:15 GMT
Port: Not available
CVE:CVE-2012-5424
Urgency:Unlikely Use
Credibility:Confirmed
Severity:Mild Damage
CVSS Base:5.0 CVSS Calculator
CVSS Version 2.0
CVSS Temporal:4.1
 
Version Summary:Cisco Secure Access Control System contains a vulnerability that could allow an unauthenticated, remote attacker to bypass TACACS+ based authentication services offered by the affected application. Updates are available.
 
 
Description
Cisco Secure Access Control System (ACS) contains a vulnerability that could allow an unauthenticated, remote attacker to bypass TACACS+ based authentication services offered by the affected application.

The vulnerability is due to improper validation of user-supplied input processed by the affected software. An unauthenticated, remote attacker could exploit this vulnerability by sending a special sequence of characters when prompted for a targeted user's password. Successful exploitation could allow the attacker to gain unauthorized access to any system that uses TACACS+  and relies on the authentication service provided by the affected software in the networking environment.

Cisco has confirmed this vulnerability and software updates are available.
 
Warning Indicators
Cisco Secure ACS versions prior to 5.4 are vulnerable.
 
IntelliShield Analysis
A successful exploit requires an attacker to know a valid username stored in the LDAP external identity store. If valid usernames have been compromised, the attacker can impersonate only those users. Administrators may consider using role-based access controls (RBAC) for users in the environment to help protect network resources in the event of a successful exploit. In addition, an attacker would likely need access to an internal, trusted network in which a targeted device may reside, decreasing the likelihood of a successful exploit.

Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
 
Vendor Announcements
Cisco has released a security advisory for Cisco bug ID CSCuc65634 at the following link: cisco-sa-20121107-acs
 
Impact
An unauthenticated, remote attacker could exploit this vulnerability to bypass authentication and impersonate a user with credentials in an Lightweight Directory Access Protocol (LDAP) external data store. Successful exploitation could allow the attacker to gain unauthorized access to any system that uses TACACS+  and relies on the authentication service provided by the affected software in the networking environment.
 
Technical Information
The vulnerability is due to improper validation of user-supplied input in the password field when the affected software is configured to use TACACS+ as the authentication protocol with an LDAP external identity store.

An unauthenticated, remote attacker could exploit this vulnerability by sending a special sequence of characters when prompted for a targeted user's password. Successful exploitation could allow the attacker to successfully authenticate to any system using TACACS+ in combination with an affected Cisco Secure ACS.
 
Safeguards
Administrators are advised to apply the appropriate updates.

Administrators may consider disabling anonymous binding on the LDAP external identity store or use a different Active Directory to help prevent exploitation of this vulnerability if these options are possible in the production environment.

Administrators are advised to monitor affected systems.
 
Patches/Software
Cisco customers with active contracts can obtain updates through the Software Center at the following link: Cisco. Cisco customers without contracts can obtain upgrades by contacting the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via e-mail at tac@cisco.com.
 
Alert History
 
Initial Release


Product Sets
 
The security vulnerability applies to the following combinations of products.

Primary Products:
CiscoCisco Secure Access Control System (ACS) 5.0 Base, .0.21 | 5.1 Base, .0.44 | 5.2 Base, .0.26 | 5.3 Base, .0.6

Associated Products:
N/A




Alerts and bulletins on the Cisco Security Intelligence Operations Portal are highlighted by analysts in the Cisco Threat Operations Center and represent a subset of the comprehensive content that is available through Cisco Security IntelliShield Alert Manager Service. This customizable threat and vulnerability alert service provides security staff with access to timely, accurate, and credible information about threats and vulnerabilities that may affect their environment.


LEGAL DISCLAIMER
The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.
Powered by  IntelliShield