Cisco Security Advisory
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AV:N/AC:H/Au:N/C:N/I:N/A:C/E:F/RL:OF/RC:C
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A vulnerability in the kernel timers in Cisco IOS Software could allow an unauthenticated, remote attacker to trigger a reload of the affected device.
The vulnerability is due to improper management of kernel timers. An attacker could exploit this vulnerability by sending crafted traffic, causing updates to timers used by the Zone-Based Firewall feature.
Cisco has confirmed the vulnerability in a security notice and released software updates.
To exploit this vulnerability, an attacker may need access to trusted, internal networks behind a firewall to send crafted traffic to the targeted device. This access requirement may reduce the likelihood of a successful exploit.
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Customers are advised to consult Cisco bug ID CSCuh25672 for a complete list of affected product versions.
Vulnerable Products
At the time this alert was first published, Cisco IOS Software version 15.4(2)T3 and prior were vulnerable. Later releases of Cisco IOS 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 can help protect affected systems from external attacks by using a solid firewall strategy.
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 2015-Feb-10
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