Cisco IOS Software contains a vulnerability in the Border Gateway Protocol (BGP) routing protocol feature. The vulnerability can be triggered when the router receives a malformed attribute from a peer on an existing BGP session. Successful exploitation of this vulnerability can cause all BGP sessions to reset. Repeated exploitation may result in an inability to route packets to BGP neighbors during reconvergence times. Cisco has released software updates that address this vulnerability. There are no workarounds for this vulnerability. This advisory is available at the following link: http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120926-bgp Note: The September 26, 2012, Cisco IOS Software Security Advisory bundled publication includes nine Cisco Security Advisories. Eight of the advisories address vulnerabilities in Cisco IOS Software, and one advisory addresses a vulnerability in Cisco Unified Communications Manager. Each Cisco IOS Software Security Advisory lists the Cisco IOS Software releases that correct the vulnerability or vulnerabilities detailed in the advisory as well as the Cisco IOS Software releases that correct all Cisco IOS Software vulnerabilities in the September 2012 bundled publication. Individual publication links are in "Cisco Event Response: Semi-Annual Cisco IOS Software Security Advisory Bundled Publication" at the following link: http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep12.html
Note: The September 26, 2012, Cisco IOS Software Security Advisory bundled publication includes nine Cisco Security Advisories. Eight of the advisories address vulnerabilities in Cisco IOS Software, and one advisory addresses a vulnerability in Cisco Unified Communications Manager. Each Cisco IOS Software Security Advisory lists the Cisco IOS Software releases that correct the vulnerability or vulnerabilities detailed in the advisory as well as the Cisco IOS Software releases that correct all Cisco IOS Software vulnerabilities in the September 2012 bundled publication.
Individual publication links are in "Cisco Event Response: Semi-Annual Cisco IOS Software Security Advisory Bundled Publication" at the following link:
http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep12.html
2. A neighbor session is established.router bgp
address-familymvpn
neighbor
router bgp2. A BGP neighbor session is established.
neighbor
Vulmon
Router# show ip bgp summary
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
10.100.1.1 4 200 26 22 199 0 0 00:14:23 23
10.200.1.1 4 300 21 51 199 0 0 00:13:40 0
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.
Router# show ip bgp summary
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
10.100.1.1 4 200 0 0 0 0 0 never Idle
10.200.1.1 4 300 0 2 0 0 0 never Idle
There are no workarounds for this vulnerability.
A reference document that may be useful is the "Protecting BGP" white paper here: http://www.cisco.com/web/about/security/intelligence/protecting_bgp.htmlWhen considering software upgrades, customers are advised to consult the Cisco Security Advisories and Responses archive at http://www.cisco.com/go/psirt and review subsequent advisories 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.
Each row of the following Cisco IOS Software table corresponds to a Cisco IOS Software train. If a particular train is vulnerable, the earliest releases that contain the fix are listed in the First Fixed Release column. The First Fixed Release for All Advisories in the September 2012 Bundled Publication column lists the earliest possible releases that correct all the published vulnerabilities in the Cisco IOS Software Security Advisory bundled publication. Cisco recommends upgrading to the latest available release, where possible.
The Cisco IOS Software Checker allows customers to search for Cisco Security Advisories that address specific Cisco IOS Software releases. This tool is available on the Cisco Security (SIO) portal at http://tools.cisco.com/security/center/selectIOSVersion.x
| Major Release | Availability of Repaired Releases | |
|---|---|---|
| Affected 12.0-Based Releases | First Fixed Release | First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication |
| There are no affected 12.0 based releases | ||
| Affected 12.2-Based Releases | First Fixed Release | First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication |
| There are no affected 12.2 based releases | ||
| Affected 12.3-Based Releases | First Fixed Release | First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication |
| There are no affected 12.3 based releases | ||
| Affected 12.4-Based Releases | First Fixed Release | First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication |
| There are no affected 12.4 based releases | ||
| Affected 15.0-Based Releases | First Fixed Release | First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication |
| There are no affected 15.0 based releases | ||
| Affected 15.1-Based Releases | First Fixed Release | First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication |
| There are no affected 15.1 based releases | ||
| Affected 15.2-Based Releases | First Fixed Release | First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication |
| 15.2GC | Not vulnerable |
Releases prior to 15.2(3)GC are vulnerable; Releases 15.2(3)GC and later are not vulnerable. First fixed in Release 15.2T |
| 15.2JA | Not vulnerable |
Not Vulnerable |
| 15.2M | Not vulnerable |
Not vulnerable |
| 15.2S | 15.2(1)S0a 15.2(1)S2 Cisco IOS XE devices: Please see Cisco IOS XE Software Availability |
15.2(1)S2 15.2(2)S1 15.2(4)S Cisco IOS XE devices: Please see Cisco IOS XE Software Availability |
| 15.2SNG | Not vulnerable |
Not vulnerable |
| 15.2T | Not vulnerable |
15.2(1)T3 15.2(2)T2 15.2(3)T2; Available on 12-OCT-12 |
| Cisco IOS XE Software Release | First Fixed Release | First Fixed Release for All Advisories in the September 2012 Cisco IOS Software Security Advisory Bundled Publication |
|---|---|---|
| 2.1.x | Not vulnerable | Vulnerable; migrate to 3.6.0S or later. |
| 2.2.x | Not vulnerable | Vulnerable; migrate to 3.6.0S or later. |
| 2.3.x | Not vulnerable | Vulnerable; migrate to 3.6.0S or later. |
| 2.4.x | Not vulnerable | Vulnerable; migrate to 3.6.0S or later. |
| 2.5.x | Not vulnerable | Vulnerable; migrate to 3.6.0S or later. |
| 2.6.x | Not vulnerable | Vulnerable; migrate to 3.6.0S or later. |
| 3.1.xS | Not vulnerable | 3.1.4S |
| 3.1.xSG | Not vulnerable | Vulnerable; migrate to 3.2.5SG or later. |
| 3.2.xS | Not vulnerable | Vulnerable; migrate to 3.6.0S or later. |
| 3.2.xSG | Not vulnerable | 3.2.5SG |
| 3.2.xSO | Not vulnerable | Vulnerable; migrate to 3.3.1SG or later. |
| 3.3.xS | Not vulnerable | Vulnerable; migrate to 3.6.0S or later. |
| 3.3xSG | Not vulnerable | 3.3.1SG |
| 3.4.xS | Not vulnerable | Vulnerable; migrate to 3.6.0S or later. |
| 3.5.xS | 3.5.2S | Vulnerable; migrate to 3.6.0S or later. |
| 3.6.xS | Not vulnerable | Not vulnerable |
| 3.7xS | Not vulnerable | Not vulnerable |
Cisco IOS XR Software Releases 4.1.0, 4.1.1, 4.1.2, 4.2.0, 4.2.1, and 4.2.2 are affected by the vulnerability described in this advisory.
| Release | Platform | CSCtz62914 SMU ID | CSCtz63248 SMU ID |
|---|---|---|---|
| 4.1.0 | c12k | AA06458 | AA06464 |
| 4.1.0 | CRS | AA06437 | AA06399 |
| 4.1.0 | asr9k | AA06449 | AA06444 |
| 4.1.1 | c12k | AA06459 | AA06465 |
| 4.1.1 | CRS | AA06438 | AA06400 |
| 4.1.1 | asr9k | AA06450 | AA06445 |
| 4.1.2 | c12k | AA06460 | AA06466 |
| 4.1.2 | CRS | AA06439 | AA06401 |
| 4.1.2 | asr9k | AA06451 | AA06446 |
| 4.2.0 | c12k | AA06461 | AA06467 |
| 4.2.0 | CRS | AA06440 | AA06402 |
| 4.2.0 | asr9k | AA06452 | AA06447 |
| 4.2.0 | asr9k (PX) | AA06453 | AA06448 |
| 4.2.1 | c12k | AA06462 | AA06546 |
| 4.2.1 | CRS | AA06441 | AA06547 |
| 4.2.1 | asr9k | AA06454 | AA06548 |
| 4.2.1 | asr9k (PX) | AA06455 | AA06549 |
| 4.2.2 | asr9k | AA06581 | AA06550 |
| 4.2.2 | asr9k (PX) | AA06582 | AA06551 |
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.
This vulnerability was found internally by Cisco during testing.
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.
| Revision 1.1 | 2012-October-04 | Added mVPN MDT note in the "Vulnerable Products" section. |
| Revision 1.0 | 2012-September-26 | Initial public release |
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