Cisco Security Advisory
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AV:A/AC:H/Au:N/C:N/I:N/A:C/E:F/RL:OF/RC:C
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A vulnerability in the packet parsing code of Cisco IOS XR Software for ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, adjacent attacker to cause a lockup and eventual reload of a Network Processor (NP) chip and a line card processing traffic.
The vulnerability is due to improper parsing of a specific packet when NetFlow sampling is configured. An attacker could exploit this vulnerability by sending a specific packet with a multicast destination MAC address through an affected device that has NetFlow sampling configured. An exploit could allow the attacker to cause a lockup and eventual reload of an NP chip and a line card processing traffic.
Cisco has confirmed the vulnerability in a security notice and released software updates.
To exploit this vulnerability, an attacker must have access to the same broadcast or collision domain of the targeted device. In addition, an attacker may need to acquire additional knowledge of the targeted device prior to attempting an exploit such as whether or not NetFlow sampling is configured. These requirements could decrease 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.
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Customers are advised to consult Cisco bug ID CSCup77750 for the most complete list of affected product versions.
Vulnerable Products
At the time this alert was first published, Cisco IOS XR Software versions 4.3(.2) and prior were vulnerable. Later releases of Cisco IOS XR Software may also be vulnerable.Products Confirmed Not Vulnerable
No other Cisco products are currently known to be affected by these vulnerabilities.
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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 network traffic for security-related network activity. Cisco NetFlow can identify such activity. For more information about Cisco NetFlow, see Introduction to Cisco IOS NetFlow - A Technical Overview.
Administrators are advised to monitor affected systems.
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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 tac@cisco.com for assistance.
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The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
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To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
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Show LessVersion Description Section Status Date 1.0 Initial Release NA Final 2014-Aug-25
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