Only devices with specific configurations are affected. Cisco devices that are running affected Cisco IOS Software or Cisco IOS XE Software versions are vulnerable when they are configured with RSVP and also have one or more VRF interfaces. A device is vulnerable if both the following criteria are met:
- At least one VRF is configured without RSVP
- At least one other interface (physical or virtual), not in the same VRF, is configured with RSVP
Some example scenarios are as follows:
- RSVP-Traffic Engineering (RSVP-TE) in Multiprotocol Label Switching (MPLS) infrastructures
- Multi-VRF infrastructures
- VRF-Lite infrastructures
To determine the Cisco IOS Software release that is running on a Cisco product, administrators can log in to the device and issue the show version command to display the system banner. The system banner confirms that the device is running Cisco IOS Software by displaying text similar to "Cisco Internetwork Operating System Software" or "Cisco IOS Software." The image name displays in parentheses, followed by "Version" and the Cisco IOS Software release name. Other Cisco devices do not have the show version command or may provide different output.
The following example identifies a Cisco product that is running Cisco IOS Software Release 15.0(1)M1 with an installed image name of C3900-UNIVERSALK9-M:
Router> show version
Cisco IOS Software, C3900 Software (C3900-UNIVERSALK9-M), Version 15.0(1)M1, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2009 by Cisco Systems, Inc.
Compiled Wed 02-Dec-09 17:17 by prod_rel_team
!--- output truncated
Additional information about Cisco IOS Software release naming conventions is available in "White Paper: Cisco IOS and NX-OS Software Reference Guide" at http://www.cisco.com/web/about/security/intelligence/ios-ref.html.
Cisco IOS-XR software is not affected by this vulnerability.
No other Cisco products are currently known to be affected by this vulnerability.