When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page, to determine exposure and a complete upgrade solution.
In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.
Cisco IOS XR Software
At the time of publication, Cisco IOS XR Software releases 6.6.3, 6.7.1, 7.1.1, 7.2.1, and later contained the fix for this vulnerability.
See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.
Cisco NX-OS Software
After upgrading a device to a fixed release of Cisco NX-OS Software, customers must apply the rule extension-header deny-all to any IPv6 ACL that is configured on the device. The rule is not enabled by default. A device should be considered vulnerable until the rule extension-header deny-all has been applied to all IPv6 ACLs that are configured on the device, even if it is running a fixed Cisco NX-OS Software release.
For detailed information about configuring the extension-header deny-all rule, see the Cisco Nexus 3600 NX-OS Unicast Routing Configuration Guide or the Cisco Nexus 9000 Series NX-OS Unicast Routing Configuration Guide.
To help customers determine their exposure to vulnerabilities in Cisco NX-OS Software, Cisco provides the Cisco Software Checker to identify any Cisco Security Advisories that impact a specific Cisco NX-OS Software release and the earliest release that fixes the vulnerabilities that are described in each advisory (“First Fixed”). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities described in all the advisories identified (“Combined First Fixed”).
Customers can use the Cisco Software Checker to search advisories in the following ways:
- Choose the software, platform, and one or more releases
- Upload a .txt file that includes a list of specific releases
- Enter the output of the show version command
After initiating a search, customers can customize the search to include all Cisco Security Advisories or one or more specific advisories.
Customers can also use the following form to determine whether a release is affected by any Cisco Security Advisory by choosing the Cisco NX-OS Software and platform and then entering a release—for example, 7.0(3)I7(5) for Cisco Nexus 3000 Series Switches or 14.0(1h) for Cisco NX-OS Software in ACI mode:
By default, the Cisco Software Checker includes results only for vulnerabilities that have a Critical or High Security Impact Rating (SIR). To include results for Medium SIR vulnerabilities, customers can use the Cisco Software Checker and check the Medium check box in the drop-down list under Impact Rating when customizing a search.