Cisco Security Advisory
Cisco IOS Software DHCPv6 Server Implementation Denial of Service Vulnerability
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AV:N/AC:L/Au:N/C:N/I:N/A:P/E:F/RL:OF/RC:C
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A vulnerability in the DHCP version 6 (DHCPv6) server implementation of Cisco IOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.
The vulnerability is due to improper handling of crafted DHCPv6 packets. An attacker could exploit this vulnerability by sending crafted DHCPv6 packets to be processed by the affected device. An exploit could allow the attacker to cause a reset of an affected process.
Cisco has confirmed the vulnerability and released software updates.
To exploit this vulnerability a remote attacker does not need to authenticate to pass the crafted DHCPv6 packets to the targeted device. This increases the likelihood of a possible 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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Cisco has released bug ID CSCun36525 for registered users, which contains additional details and an up-to-date list of affected product versions.
Vulnerable Products
At the time this alert was first published, Cisco 9000 Series Aggregation Services Router (ASR) version 5.2.0 (Base) devices running Cisco IOS Software were vulnerable. Other versions may also be affected.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 affected systems.
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Cisco customers with active contracts can obtain updates through the Software Center at the following link: Cisco. Cisco customers without contracts can obtain upgrades by contacting the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at tac@cisco.com.
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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-Sep-18
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