Cisco Adaptive Security Appliance Software contains a vulnerability that could allow an unauthenticated, remote attacker to modify the phone proxy connection database. Software updates are not available.
A vulnerability in the phone proxy feature of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to temporarily insert an invalid entry in the phone proxy connection database.
The vulnerability is due to the acceptance of an untrusted certificate. An attacker could exploit this vulnerability by submitting a crafted certificate to the phone proxy process. An exploit could allow the attacker to insert an invalid entry into the phone proxy connection database.
Cisco has confirmed the vulnerability in a security notice; however, software updates are not available.
At the time this alert was first published, Cisco ASA Software Release 220.127.116.11 and prior were vulnerable. Later releases of Cisco ASA Software may also be vulnerable.
To exploit this vulnerability, it is likely that an attacker would need access to trusted, internal networks to submit a crafted certificate to the phone proxy process on an affected device. This access requirement limits 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.
Cisco released a security notice at the following link: CVE-2013-6682
Customers are advised to consult Cisco bug ID CSCui33299 for the most complete list of affected product versions.
An unauthenticated, remote attacker could exploit the vulnerability to manipulate entries in the phone proxy connection database used on a targeted device. A successful exploit could be used to conduct further attacks.
The vulnerability is due to insufficient validation of certificates being accepted by a device running an affected version of Cisco ASA Software.
An unauthenticated, remote attacker could exploit this vulnerability by submitting a crafted certificate to the phone proxy process. An exploit could allow the attacker to insert an invalid entry into the phone proxy connection database, which could be used to conduct further attacks.
Administrators are advised to contact the vendor regarding future updates and releases.
Administrators are advised to allow only trusted users to have network access.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators are advised to monitor affected systems.
The security vulnerability applies to the following combinations of products.
Cisco Adaptive Security Appliance (ASA) Software
9.0 .1, .2, .2.10, .3, .3.6
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.