Cisco IOS XE Software contains a vulnerability that could allow an authenticated, remote attacker to cause a denial of service condition. Updates are available.
A vulnerability in a DHCP function that assigns IP addresses to AAA clients on Cisco IOS XE Software could allow an authenticated, remote attacker to cause a reload of the affected device.
The vulnerability is due to improper processing of AAA packets that require IP address assignment from a DHCP pool. An attacker could exploit this vulnerability by sending AAA packets to a device configured to authenticate and assign an address from a DHCP pool. An exploit could allow the attacker to cause a reload of the affected device.
Cisco has confirmed the vulnerability in a security notice and released software updates.
At the time this alert was first published, Cisco IOS XE Software version 3.8S(.2) and prior were vulnerable. Later releases of Cisco IOS XE Software may also be vulnerable.
To exploit this vulnerability, an attacker would need to authenticate to the targeted device. This access requirement decreases 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 has released a security notice at the following link: CVE-2013-6692
Customers are advised to consult Cisco bug ID CSCuh04949 for the most complete list of affected product versions.
An authenticated, remote attacker could exploit this vulnerability to cause an affected device to reload, resulting in a DoS condition.
The vulnerability is due to improper processing of AAA packets that require IP address assignment from a DHCP pool.
An authenticated, remote attacker could exploit this vulnerability by sending AAA packets to a targeted device configured to authenticate and assign an address from a DHCP pool. An exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
Administrators are advised to apply the appropriate updates
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.
Cisco customers with active contracts should contact their Cisco support team for assistance in upgrading to a software version that includes fixes for this vulnerability. Cisco customers without contracts may contact the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at email@example.com for assistance.
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.