Cisco Security Advisory
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AV:N/AC:M/Au:S/C:N/I:N/A:C/E:F/RL:OF/RC:C
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A vulnerability in the Layer 2 Tunneling Protocol (L2TP) module of Cisco IOS XE on Cisco ASR 1000 Series Routers could allow an authenticated, remote attacker to cause a reload of the processing ESP card.
The vulnerability occurs during the processing of a malformed L2TP packet. An attacker could exploit this vulnerability by sending malformed L2TP packets over an established L2TP session. An exploit could allow the attacker to cause a reload of the affected ESP card.
Cisco has confirmed the vulnerability in a security notice and released software updates.
To exploit this vulnerability, an attacker must authenticate to a targeted device. This access requirement decreases the likelihood of a successful exploit attempt.
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 CSCun09973 for a complete list of affected product versions.
Vulnerable Products
At the time this alert was first published, Cisco IOS XE Software versions 3.10S(.2) and prior were vulnerable. Later releases of Cisco IOS XE 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.
It is critical to prevent unauthorized direct communication to network devices. Restrict network traffic destined for the network infrastructure to protect against reconnaissance and denial of service attacks. For configuration details, see Protecting Your Core: Infrastructure Protection Access Control Lists.
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-Apr-28
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