Cisco Security Advisory: Cisco uBR10012 Series Devices SNMP Vulnerability
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Cisco Security Advisory: Cisco uBR10012 Series Devices SNMP
Vulnerability
Advisory ID: cisco-sa-20080924-ubr
http://www.cisco.com/warp/public/707/cisco-sa-20080924-ubr.shtml
Revision 1.0
For Public Release 2008 September 24 1600 UTC (GMT)
- ---------------------------------------------------------------------
Summary
=======
Cisco uBR10012 series devices automatically enable Simple Network
Management Protocol (SNMP) read/write access to the device if
configured for linecard redundancy. This can be exploited by an
attacker to gain complete control of the device. Only Cisco uBR10012
series devices that are configured for linecard redundancy are
affected.
Cisco has released free software updates that address this
vulnerability. Workarounds that mitigate this vulnerability are
available.
This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20080924-ubr.shtml
NOTE: The September 24, 2008 IOS Advisory bundled publication
includes twelve Security Advisories. Eleven of the advisories address
vulnerabilities in Cisco's IOS^ software, and one advisory addresses
vulnerabilities in Cisco Unified Communications Manager. Each
Advisory lists the releases that correct the vulnerability described
in the Advisory. Please reference the following software table to
find a release that fixes all published IOS software Advisories as of
September 24th, 2008:
http://www.cisco.com/warp/public/707/cisco-sa-20080924-bundle.shtml
Individual publication links are listed below:
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-iosips.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-ssl.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-sip.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-cucm.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-vpn.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-mfi.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-ipc.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-ubr.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-multicast.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-sccp.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-iosfw.shtml
* http://www.cisco.com/warp/public/707/cisco-sa-20080924-l2tp.shtml
Affected Products
=================
Vulnerable Products
+------------------
Cisco uBR10012 series devices that are running Cisco IOS and
configured for linecard redundancy are affected. Cisco uBR10012
series devices can be identified by issuing the show version command.
The following example shows output from a Cisco uBR10012 series
device running Cisco IOS software release 12.3(17b)BC7:
ubr10k#show version | include IOS
IOS (tm) 10000 Software (UBR10K-K8P6U2-M), Version 12.3(17b)BC7, RELEASE
SOFTWARE (fc1)
ubr10k#
Please refer to the document entitled "White Paper: Cisco IOS
Reference Guide" for additional information on the Cisco IOS release
naming conventions. This document is available at the following link:
http://www.cisco.com/warp/public/620/1.html
A Cisco uBR10012 series device configured for linecard redundancy
will have a line similar to the following in the output of show
running-config command:
member subslot <slot>/<card> working
or
hccp <group> protect <worker-member-id> <worker-ip-address>
Any version of Cisco IOS prior to the versions listed in the Software
Versions and Fixes section below is vulnerable.
Products Confirmed Not Vulnerable
+--------------------------------
Cisco uBR10012 series devices that are not configured for linecard
redundancy are not affected.
Cisco 10000 series devices are not affected even if they are
configured for linecard redundancy.
Other uBR platforms are not affected.
No other Cisco products are currently known to be affected by this
vulnerability.
Details
=======
Cisco uBR10012 series devices need to communicate with an RF Switch
when configured for linecard redundancy. This communication is based
on SNMP (Simple Network Management Protocol). When linecard
redundancy is enabled on a Cisco uBR10012 series device, SNMP is also
automatically enabled with a default community string of private that
has read/write privileges. Since there are no access restrictions on
this community string, it may be exploited by an attacker to gain
complete control of the device.
Changing the default community string, adding access restrictions on
SNMP or doing both will mitigate this vulnerability. The recommended
mitigation is to do both.
This vulnerability is documented in the Cisco Bug ID CSCek57932
and has been assigned Common Vulnerabilities and Exposures (CVE) ID
CVE-2008-3807.
Vulnerability Scoring Details
=============================
Cisco has provided scores for the vulnerabilities in this advisory
based on the Common Vulnerability Scoring System (CVSS). The CVSS
scoring in this Security Advisory is done in accordance with CVSS
version 2.0.
CVSS is a standards-based scoring method that conveys vulnerability
severity and helps determine urgency and priority of response.
Cisco has provided a base and temporal score. Customers can then
compute environmental scores to assist in determining the impact of
the vulnerability in individual networks.
Cisco has provided an FAQ to answer additional questions regarding
CVSS at
http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html
Cisco has also provided a CVSS calculator to help compute the
environmental impact for individual networks at
http://intellishield.cisco.com/security/alertmanager/cvss
CSCek57932 - SNMP enabled after redundancy is configured
CVSS Base Score - 10
Access Vector - Network
Access Complexity - Low
Authentication - None
Confidentiality Impact - Complete
Integrity Impact - Complete
Availability Impact - Complete
CVSS Temporal Score - 8.3
Exploitability - Functional
Remediation Level - Official-Fix
Report Confidence - Confirmed
Impact
======
Successful exploitation of the vulnerability may allow an attacker to
gain complete control of the device.
Software Versions and Fixes
===========================
When considering software upgrades, also consult
http://www.cisco.com/go/psirt and any subsequent advisories to
determine exposure and a complete upgrade solution.
In all cases, customers should exercise caution to be certain the
devices to be upgraded contain sufficient memory and that current
hardware and software configurations will continue to be supported
properly by the new release. If the information is not clear, contact
the Cisco Technical Assistance Center (TAC) or your contracted
maintenance provider for assistance.
Each row of the Cisco IOS software table (below) names a Cisco IOS
release train. If a given release train is vulnerable, then the
earliest possible releases that contain the fix (along with the
anticipated date of availability for each, if applicable) are listed
in the "First Fixed Release" column of the table. The "Recommended
Release" column indicates the releases which have fixes for all the
published vulnerabilities at the time of this Advisory. A device
running a release in the given train that is earlier than the release
in a specific column (less than the First Fixed Release) is known to
be vulnerable. Cisco recommends upgrading to a release equal to or
later than the release in the "Recommended Releases" column of the
table.
+-------------------------------------------------------------------+
| Major Release | Availability of Repaired Releases |
|--------------------+----------------------------------------------|
| Affected | | Recommended |
| 12.0-Based | First Fixed Release | Release |
| Releases | | |
|-------------------------------------------------------------------|
| There are no affected 12.0 based releases |
|-------------------------------------------------------------------|
| Affected | | Recommended |
| 12.1-Based | First Fixed Release | Release |
| Releases | | |
|-------------------------------------------------------------------|
| There are no affected 12.1 based releases |
|-------------------------------------------------------------------|
| Affected | | Recommended |
| 12.2-Based | First Fixed Release | Release |
| Releases | | |
|--------------------+------------------------------+---------------|
| 12.2 | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2B | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| | | 12.2(33)SCA1 |
| | | |
| | Vulnerable; migrate to any | 12.3(23)BC4 |
| 12.2BC | release in 12.3 | |
| | | 12.4(15)T7 |
| | | |
| | | 12.4(18c) |
|--------------------+------------------------------+---------------|
| 12.2BW | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2BX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2BY | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2BZ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| | | 12.2(33)SCA1 |
| | | |
| | Vulnerable; migrate to any | 12.3(23)BC4 |
| 12.2CX | release in 12.3 | |
| | | 12.4(15)T7 |
| | | |
| | | 12.4(18c) |
|--------------------+------------------------------+---------------|
| | | 12.2(33)SCA1 |
| | | |
| | Vulnerable; migrate to any | 12.3(23)BC4 |
| 12.2CY | release in 12.3 | |
| | | 12.4(15)T7 |
| | | |
| | | 12.4(18c) |
|--------------------+------------------------------+---------------|
| 12.2CZ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2DA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2DD | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2DX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2EW | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2EWA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2EX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2EY | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2EZ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2FX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2FY | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2FZ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2IRB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2IXA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2IXB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2IXC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2IXD | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2IXE | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2IXF | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2IXG | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2JA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2JK | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2MB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2MC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2S | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SBC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SCA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SE | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SEA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SEB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SEC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SED | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SEE | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SEF | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SEG | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SG | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SGA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SL | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SM | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SO | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SRA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SRB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SRC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SU | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SV | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SVA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SVC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SVD | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SW | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SXA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SXB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SXD | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SXE | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SXF | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SXH | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SY | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2SZ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2T | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2TPC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XD | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XE | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| | | 12.2(33)SCA1 |
| | | |
| | Vulnerable; migrate to any | 12.3(23)BC4 |
| 12.2XF | release in 12.3 | |
| | | 12.4(15)T7 |
| | | |
| | | 12.4(18c) |
|--------------------+------------------------------+---------------|
| 12.2XG | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XH | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XI | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XJ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XK | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XL | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XM | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XN | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XNA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XNB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XO | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XQ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XR | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XS | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XT | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XU | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XV | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2XW | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YD | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YE | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YF | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YG | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YH | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YJ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YK | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YL | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YM | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YN | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YO | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YP | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YQ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YR | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YS | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YT | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YU | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YV | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YW | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YY | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2YZ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZD | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZE | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZF | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZG | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZH | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZJ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZL | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZP | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZU | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZY | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.2ZYA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| Affected | | Recommended |
| 12.3-Based | First Fixed Release | Release |
| Releases | | |
|--------------------+------------------------------+---------------|
| 12.3 | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3B | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| | 12.3(17b)BC8 | |
| 12.3BC | | 12.3(23)BC4 |
| | 12.3(21)BC | |
|--------------------+------------------------------+---------------|
| 12.3BW | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3EU | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3JA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3JEA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3JEB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3JEC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3JK | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3JL | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3JX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3T | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3TPC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3VA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XB | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XC | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XD | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XE | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XF | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XG | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XI | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XJ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XK | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XL | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XQ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XR | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XS | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XU | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XW | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XY | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3XZ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YD | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YF | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YG | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YH | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YI | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YJ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YK | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YM | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YQ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YS | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YT | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YU | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YX | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3YZ | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| 12.3ZA | Not Vulnerable | |
|--------------------+------------------------------+---------------|
| Affected | | Recommended |
| 12.4-Based | First Fixed Release | Release |
| Releases | | |
|-------------------------------------------------------------------|
| There are no affected 12.4 based releases |
+-------------------------------------------------------------------+
Workarounds
===========
Changing SNMP community string and restricting access
+----------------------------------------------------
By default, Cisco uBR10012 series devices that are configured for
linecard redundancy use a community string of private. This community
string can be changed in Cisco IOS versions 12.3(13)BC and later. It
is recommended to change the community string and apply access
control restrictions that only permit authorized devices SNMP access
to the device.
The following configuration example provides operators with
information on changing the community string and adding SNMP access
control restrictions using an access control list (ACL).
access-list 90 permit host <RF-Switch-IP-1>
access-list 90 permit host <RF-Switch-IP-2>
access-list 90 permit host <up-converter-IP-if-exists>
access-list 90 deny any
redundancy
linecard-group 1 cable
rf-switch snmp-community <RF-Switch-SNMP-community>
snmp-server community <RF-Switch-SNMP-community> rw 90
When the SNMP community is changed on a Cisco uBR10012 device, is
must also be changed on the RF Switch. It can be changed by the
following command:
set SNMP COMMUNITY <RF-Switch-SNMP-community>
If there is an up-converter in the network, the SNMP community used
by the up-converter must also be changed after changing the community
string on the Cisco uBR10012 device. Information on changing the
community string used by the up-converter can be found at the
following link:
http://www.cisco.com/en/US/tech/tk86/tk804/technologies_tech_note09186a00801f7622.shtml#communication
If the Cisco IOS version does not support changing the community
string, access control restrictions can be applied to the default
community string. The following configuration example provides
operators with information on applying access control restrictions to
the default community string.
access-list 90 permit host <RF-Switch-IP-1>
access-list 90 permit host <RF-Switch-IP-2>
access-list 90 permit host <up-converter-IP-if-exists>
access-list 90 deny any
snmp-server community private rw 90
Using Infrastructure ACLs at Network Boundary
+--------------------------------------------
Although it is often difficult to block traffic transiting your
network, it is possible to identify traffic which should never be
allowed to target your infrastructure devices and block that traffic
at the border of your network. iACLs are a network security best
practice and should be considered as a long-term addition to good
network security as well as a workaround for this specific
vulnerability. The iACL example shown below should be included as
part of the deployed infrastructure access-list which will protect
all devices with IP addresses in the infrastructure IP address range:
!-- Permit SNMP (UDP port 161) packets from trusted hosts
!-- destined to infrastructure addresses.
!
access-list 150 permit udp TRUSTED_HOSTS MASK INFRASTRUCTURE_ADDRESSES MASK
eq 161
!
!-- Deny SNMP (UDP port 161) packets from all other sources
!-- destined to infrastructure addresses.
!
access-list 150 deny udp any INFRASTRUCTURE_ADDRESSES MASK eq 161
!
!-- Permit/deny all other Layer 3 and Layer 4 traffic in
!-- accordance with existing security policies and
!-- configurations.
!
!-- Permit all other traffic to transit the device.
!
access-list 150 permit ip any any
!
!-- Apply iACL to interfaces in the ingress direction.
!
interface GigabitEthernet0/0
ip access-group 150 in
!
The white paper entitled "Protecting Your Core: Infrastructure
Protection Access Control Lists" presents guidelines and recommended
deployment techniques for infrastructure protection access lists.
This white paper can be obtained here:
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00801a1a55.shtml
Additional Mitigation Techniques
+-------------------------------
Additional mitigation techniques that can be deployed on Cisco
devices within the network are available in the Cisco Applied
Mitigation Bulletin companion document for this advisory, which is
available at the following link:
http://www.cisco.com/warp/public/707/cisco-amb-20080924-ipc-and-ubr.shtml
Obtaining Fixed Software
========================
Cisco has released free software updates that address these
vulnerabilities. Prior to deploying software, customers should
consult their maintenance provider or check the software for feature
set compatibility and known issues specific to their environment.
Customers may only install and expect support for the feature sets
they have purchased. By installing, downloading, accessing or
otherwise using such software upgrades, customers agree to be bound
by the terms of Cisco's software license terms found at
http://www.cisco.com/en/US/products/prod_warranties_item09186a008088e31f.html
or as otherwise set forth at Cisco.com Downloads at
http://www.cisco.com/public/sw-center/sw-usingswc.shtml
Do not contact psirt@xxxxxxxxx or security-alert@xxxxxxxxx for
software upgrades.
Customers with Service Contracts
+-------------------------------
Customers with contracts should obtain upgraded software through
their regular update channels. For most customers, this means that
upgrades should be obtained through the Software Center on Cisco's
worldwide website at http://www.cisco.com.
Customers using Third Party Support Organizations
+------------------------------------------------
Customers whose Cisco products are provided or maintained through
prior or existing agreements with third-party support organizations,
such as Cisco Partners, authorized resellers, or service providers
should contact that support organization for guidance and assistance
with the appropriate course of action in regards to this advisory.
The effectiveness of any workaround or fix is dependent on specific
customer situations, such as product mix, network topology, traffic
behavior, and organizational mission. Due to the variety of affected
products and releases, customers should consult with their service
provider or support organization to ensure any applied workaround or
fix is the most appropriate for use in the intended network before it
is deployed.
Customers without Service Contracts
+----------------------------------
Customers who purchase direct from Cisco but do not hold a Cisco
service contract, and customers who purchase through third-party
vendors but are unsuccessful in obtaining fixed software through
their point of sale should acquire upgrades by contacting the Cisco
Technical Assistance Center (TAC). TAC contacts are as follows.
* +1 800 553 2447 (toll free from within North America)
* +1 408 526 7209 (toll call from anywhere in the world)
* e-mail: tac@xxxxxxxxx
Customers should have their product serial number available and be
prepared to give the URL of this notice as evidence of entitlement to
a free upgrade. Free upgrades for non-contract customers must be
requested through the TAC.
Refer to http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml
for additional TAC contact information, including localized telephone
numbers, and instructions and e-mail addresses for use in various
languages.
Exploitation and Public Announcements
=====================================
The Cisco PSIRT is not aware of any public announcements or malicious
use of the vulnerability described in this advisory.
This vulnerability was found internally.
Status of this Notice: FINAL
============================
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY
KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE
INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS
AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS
DOCUMENT AT ANY TIME.
A stand-alone copy or Paraphrase of the text of this document that
omits the distribution URL in the following section is an
uncontrolled copy, and may lack important information or contain
factual errors.
Distribution
============
This advisory is posted on Cisco's worldwide website at :
http://www.cisco.com/warp/public/707/cisco-sa-20080924-ubr.shtml
In addition to worldwide web posting, a text version of this notice
is clear-signed with the Cisco PSIRT PGP key and is posted to the
following e-mail and Usenet news recipients.
* cust-security-announce@xxxxxxxxx
* first-bulletins@xxxxxxxxxxxxxxx
* bugtraq@xxxxxxxxxxxxxxxxx
* vulnwatch@xxxxxxxxxxxxx
* cisco@xxxxxxxxxxxxxxxxx
* cisco-nsp@xxxxxxxxxxxxxxx
* full-disclosure@xxxxxxxxxxxxxxxxx
* comp.dcom.sys.cisco@xxxxxxxxxxxxxxxxxx
Future updates of this advisory, if any, will be placed on Cisco's
worldwide website, but may or may not be actively announced on
mailing lists or newsgroups. Users concerned about this problem are
encouraged to check the above URL for any updates.
Revision History
================
+---------------------------------------+
| Revision | | Initial |
| 1.0 | 2008-Sep-24 | public |
| | | release. |
+---------------------------------------+
Cisco Security Procedures
=========================
Complete information on reporting security vulnerabilities in Cisco
products, obtaining assistance with security incidents, and
registering to receive security information from Cisco, is available
on Cisco's worldwide website at
http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html
This includes instructions for press inquiries regarding Cisco
security notices. All Cisco security advisories are available at
http://www.cisco.com/go/psirt
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