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Cisco Security Advisory: Cisco ONS Platform Crafted Packet
Vulnerability
Advisory ID: cisco-sa-20090114-ons
http://www.cisco.com/warp/public/707/cisco-sa-20090114-ons.shtml
Revision 1.0
For Public Release 2009 January 14 1600 UTC (GMT)
- ---------------------------------------------------------------------
Summary
======
The Cisco ONS 15300 series Edge Optical Transport Platform, the Cisco
ONS 15454 Optical Transport Platform, the Cisco ONS 15454 SDH
Multiservice Platform, and the Cisco ONS 15600 Multiservice Switching
Platform contains a vulnerability when processing TCP traffic streams
that may result in a reload of the device control card.
Cisco has released free software updates that address this
vulnerability.
There are no workarounds that mitigate this vulnerability. Several
mitigations exist that can limit the exposure of this vulnerability.
This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20090114-ons.shtml
Affected Products
================
Vulnerable Products
+------------------
The following Cisco ONS products are vulnerable if running affected
software versions:
* Cisco ONS 15310-CL and 15310-MA
* Cisco ONS 15327
* Cisco ONS 15454 and 15454 SDH
* Cisco ONS 15600
Consult the section "Software Versions and Fixes" within this
advisory for affected software versions. To determine your software
version, view the Help > About window on the CTC management
software).
Products Confirmed Not Vulnerable
+--------------------------------
The following Cisco ONS products are confirmed not vulnerable:
* Cisco ONS 15800 Series
* Cisco ONS 15500 Series Extended Service Platform
* Cisco ONS 15302
* Cisco ONS 15305
* Cisco ONS 15200 Series Metro DWDM Systems
* Cisco ONS 15190 Series IP Transport Concentrator
No other Cisco products are currently known to be affected by this
vulnerability.
Details
======
The affected Cisco 15310-CL, 15310-MA, ONS 15327, ONS 15454, ONS
15454 SDH, and ONS 15600 hardware is managed through the CTX,
CTX2500, XTC, TCC/TCC+/TCC2/TCC2P, TCCi/TCC2/TCC2P, and TSC control
cards respectively. These control cards are usually connected to a
Data Communications Network (DCN). In this context the term DCN is
used to denote the network that transports management information
between a management station and the network entity (NE). This
definition of DCN is sometimes referred to as Management
Communication Network (MCN). The DCN is usually physically or
logically separated from the optical data network and isolated from
the Internet. This limits the exposure to the exploitation of this
vulnerability from the Internet.
A crafted stream of TCP traffic to the control cards on a node will
result in a reset of the corresponding control cards on this node. A
complete 3-way handshake is required on any open TCP port to be able
to exploit this vulnerability.
The timing for the data channels traversing the switch is provided by
the control cards.
When an active and a standby Cisco ONS 15310-MA, ONS 15310-CL, ONS
15327, ONS 15454 or ONS 15454 SDH control card reloads at the same
time, the synchronous data channels traversing the switch drop
traffic until the card comes back online. Asynchronous data channels
traversing the switch are not impacted. Manageability functions
provided by the network element using the CTX, CTX2500, XTC or TCC/
TCC+/TCC2/TCC2P control cards are not available until the control
card comes back online.
On the Cisco ONS 15600 hardware, whenever both the active and standby
control cards are rebooting at the same time, there is no impact to
the data channels traversing the switch because the TSC performs a
software reset which does not impact the timing being provided by the
TSC for the data channels.
Manageability functions provided by the network element through the
TSC control cards are not available until the control card comes back
online.
This vulnerability is documented in Cisco bug ID CSCsr41128
and has been assigned Common Vulnerabilities and Exposures (CVE)
identifier CVE-2008-3818.
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
CVSS Base Score - 7.8
Access Vector : Network
Access Complexity : Low
Authentication : None
Confidentiality Impact: None
Integrity Impact : None
Availability Impact : Complete
CVSS Temporal Score - 6.4
Exploitability : Functional
Remediation Level : Official-Fix
Report Confidence : Confirmed
Impact
=====
Successful exploitation of this vulnerability will result in a reset
of the node's control card. Repeated attempts to exploit this
vulnerability could result in a sustained DoS condition, dropping the
synchronous data channels traversing the switch (Cisco ONS 15310-MA,
ONS 15310-CL, ONS 15327, ONS 15454, ONS 15454 SDH) and preventing
manageability functions provided by the network element control cards
(all ONS switches) until the control card comes back online.
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.
+-------------------------------------------------------------------------+
| Affected Major Release | First Fixed Release |
|---------------------------------+---------------------------------------|
| 7.0 | Note: Releases prior to 7.0.2 are not |
| | vulnerable. First fixed in 7.0.7 |
|---------------------------------+---------------------------------------|
| 7.2 | Note: Releases prior to 7.2.2 are not |
| | vulnerable. First fixed in 7.2.3 |
|---------------------------------+---------------------------------------|
| 8.0 | Vulnerable; migrate to 8.5.3 or |
| | later. |
|---------------------------------+---------------------------------------|
| 8.5 | Note: Releases prior to 8.5.1 are not |
| | vulnerable. First fixed in 8.5.3 |
|---------------------------------+---------------------------------------|
| 9.0 | Not vulnerable. |
+-------------------------------------------------------------------------+
Note: Releases prior to 7.0 are not affected by this vulnerability.
Workarounds
==========
There are no workarounds for this vulnerability. The following
general mitigation actions help prevent remote exploitation:
* Isolate DCN:
Ensuring the DCN is physically or logically separated from the
customer network and isolated from the Internet will limit the
exposure to the exploitation of these vulnerabilities from the
Internet or customer networks.
* Apply Transit Access Control Lists:
Apply access control lists (ACLs) on routers / switches /
firewalls installed in front of the vulnerable network devices
such that TCP/IP traffic destined for the CTX, CTX2500, XTC, TCC2
/TCC2+/TCC2P, or TSC control cards on the ONS is allowed only
from the network management workstations.
For examples on how to apply ACLs on Cisco routers, refer to the
white paper "Transit Access Control Lists: Filtering at Your
Edge", which is available at the following link:
http://www.cisco.com/en/US/customer/tech/tk648/tk361/technologies_white_paper09186a00801afc76.shtml
Additional mitigations 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-20090114-ons.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@cisco.com or security-alert@cisco.com 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@cisco.com
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/en/US/support/tsd_cisco_worldwide_contacts.html
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 by reviewing Cisco TAC service requests.
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-20090114-ons.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@cisco.com
* first-bulletins@lists.first.org
* bugtraq@securityfocus.com
* vulnwatch@vulnwatch.org
* cisco@spot.colorado.edu
* cisco-nsp@puck.nether.net
* full-disclosure@lists.grok.org.uk
* comp.dcom.sys.cisco@newsgate.cisco.com
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 | 2009-January-14 | 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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