Cisco IOS XE Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
A vulnerability in the Multiprotocol Label Switching (MPLS) IP fragmentation function of Cisco IOS XE could allow an unauthenticated, remote attacker to cause the Cisco Packet Processor to crash.
The vulnerability is due to input validation processing of the crafted MPLS IP packets. An attacker could exploit this vulnerability by injecting specifically crafted MPLS IP packets that are subject to MPLS fragmentation. An exploit could allow the attacker to cause the Cisco Packet Processor process to crash in Cisco IOS XE software.
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 3.7S(.1) and prior were vulnerable. Later releases of Cisco Cisco IOS XE Software may also be vulnerable.
To exploit this vulnerability, it is likely that an attacker would need access to trusted, internal networks to send crafted MPLS IP packets to the targeted device to be processed. This access requirement may reduce 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-2013-6981
Customers are advised to consult Cisco bug ID CSCul00709 for the most complete list of affected product versions.
An unauthenticated, remote attacker could exploit this vulnerability to cause the Cisco Packet Processor on an affected device to crash, resulting in a denial of service (DoS) condition.
The vulnerability is due to insufficient validation of user supplied input while processing crafted MPLS IP packets by the affected software.
An unauthenticated, remote attacker could exploit this vulnerability by injecting specifically crafted MPLS IP packets that are subject to MPLS fragmentation. A successful exploit could allow the attacker to cause the Cisco Packet Processor process to crash in Cisco IOS XE Software, resulting in a DoS condition on an affected device.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
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 firstname.lastname@example.org 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.