[AusNOG] Cisco Security Advisory: Cisco Content Services Gateway Vulnerabilities
Bruce Forster
bruce at tubes.net.au
Thu Jan 27 11:40:31 EST 2011
I guess next your going to complain about the BGP Update Report
I like having them on ausnog tbh, why even whinge about it?
-bruce
-----Original Message-----
From: ausnog-bounces at lists.ausnog.net
[mailto:ausnog-bounces at lists.ausnog.net] On Behalf Of Phil Pierotti
Sent: Thursday, 27 January 2011 8:20 AM
To: ausnog at ausnog.net
Subject: Re: [AusNOG] Cisco Security Advisory: Cisco Content Services
Gateway Vulnerabilities
Seriously folks, is this *really* necessary?
Are there AUSnogERs out there who do not know about the cisco-nsp mailing
list?
Regards,
Phil Pierotti
Network Operations Manager
Platform Networks
www.platformnetworks.net
ph. 1300 854 678
-----Original Message-----
From: ausnog-bounces at lists.ausnog.net
[mailto:ausnog-bounces at lists.ausnog.net] On Behalf Of Cisco Systems Product
Security Incident Response Team
Sent: Thursday, 27 January 2011 2:39 AM
To: ausnog at ausnog.net
Cc: psirt at cisco.com
Subject: [AusNOG] Cisco Security Advisory: Cisco Content Services Gateway
Vulnerabilities
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Hash: SHA256
Cisco Security Advisory: Cisco Content Services Gateway Vulnerabilities
Advisory ID: cisco-sa-20110126-csg2
http://www.cisco.com/warp/public/707/cisco-sa-20110126-csg2.shtml
Revision 1.0
For Public Release 2011 January 26 1600 UTC (GMT)
+---------------------------------------------------------------------
Summary
=======
A service policy bypass vulnerability exists in the Cisco Content Services
Gateway - Second Generation (CSG2), which runs on the Cisco Service and
Application Module for IP (SAMI). Under certain configurations this
vulnerability could allow:
* Customers to access sites that would normally match a billing
policy to be accessed without being charged to the end customer
* Customers to access sites that would normally be denied based on
configured restriction policies
Additionally, Cisco IOS Software Release 12.4(24)MD1 on the Cisco
CSG2 contains two vulnerabilities that can be exploited by a remote,
unauthenticated attacker to create a denial of service condition that
prevents traffic from passing through the CSG2. These vulnerabilities
require only a single content service to be active on the Cisco CSG2 and can
be exploited via crafted TCP packets. A three-way handshake is not required
to exploit either of these vulnerabilities.
Workarounds that mitigate these vulnerabilities are not available.
This advisory is posted at
http://www.cisco.com/warp/public/707/cisco-sa-20110126-csg2.shtml.
Affected Products
=================
The service policy bypass vulnerability affects all versions of the Cisco
IOS Software for the CSG2 prior to the first fixed release, as indicated in
the "Software Versions and Fixes" section of this advisory.
The two denial of service vulnerabilities only affect Cisco IOS Software
Release 12.4(24)MD1 on the Cisco CSG2. No other Cisco IOS Software releases
are affected.
Vulnerable Products
+------------------
To determine the version of Cisco IOS Software that is running on the Cisco
CSG2, issue the "show module" command from Cisco IOS Software on the switch
on which the Cisco CSG2 module is installed to identify what modules and
sub-modules are installed on the system.
Cisco CSG2 runs on the Cisco Service and Application Module for IP
(SAMI) card, and is identified in the following example in slot 2 via the
WS-SVC-SAMI-BB-K9 identification:
C7600#show module
Mod Ports Card Type Model
Serial No.
--- ----- -------------------------------------- ------------------
-----------
1 2 Supervisor Engine 720 (Active) WS-SUP720-3BXL
JAF1226ARQS
2 1 SAMI Module (csgk9) WS-SVC-SAMI-BB-K9
SAD113906P1
4 48 CEF720 48 port 10/100/1000mb Ethernet WS-X6748-GE-TX
SAL1127T6XY
Mod MAC addresses Hw Fw Sw
Status
--- ---------------------------------- ------ ------------ ------------
-------
1 001e.be6e.a018 to 001e.be6e.a01b 5.6 8.5(2) 12.2(33)SRC5
Ok
2 001d.45f8.f3dc to 001d.45f8.f3e3 2.1 8.7(0.22)FW1 12.4(2010040
Ok
4 001c.587a.ef20 to 001c.587a.ef4f 2.6 12.2(14r)S5 12.2(33)SRC5
Ok
Mod Sub-Module Model Serial Hw
Status
---- --------------------------- ------------------ ----------- -------
-------
1 Policy Feature Card 3 WS-F6K-PFC3BXL JAF1226BNQM 1.8
Ok
1 MSFC3 Daughterboard WS-SUP720 JAF1226BNMC 3.1
Ok
2 SAMI Daughterboard 1 SAMI-DC-BB SAD114400L9 1.1
Other
2 SAMI Daughterboard 2 SAMI-DC-BB SAD114207FU 1.1
Other
4 Centralized Forwarding Card WS-F6700-CFC SAL1029VGFK 2.0
Ok
Mod Online Diag Status
---- -------------------
1 Pass
2 Pass
4 Pass
C7600#
After locating the correct slot, issue the "session slot <module number>
processor <3-9>" command to open a console connection to the respective
Cisco CSG2. Once connected to the Cisco CSG2, perform the "show version"
command:
The following example shows that the Cisco CSG2 is running software Release
12.4(24)MD1:
CSG2#show version
Cisco IOS Software, SAMI Software (SAMI-CSGK9-M), Version 12.4(24)MD1,
RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Wed 07-Apr-10 09:50 by prod_rel_team
--- output truncated ---
Products Confirmed Not Vulnerable
+--------------------------------
The Cisco Content Services Gateway - 1st Generation (CSG) is not affected by
these vulnerabilities.
No other Cisco products are currently known to be affected by these
vulnerabilities.
Details
=======
The Cisco Content Services Gateway - Second Generation (CSG2) provides
intelligent network capabilities such as flexible policy management and
billing based on deep-packet inspection, as well as subscriber and
application awareness capabilities that enable mobile operators to quickly
and easily offer value-added, differentiated services over their mobile data
networks.
The service policy bypass vulnerability affects configurations that allow
end users to first access non-accounted or billed sites. After a user
accesses a non-accounted site, it is possible to access other sites that are
defined by a billing service policy or to access sites that may be blocked
by other policies by sending specially crafted HTTP packets.
This vulnerability only affects HTTP content traffic. HTTPS and other
traffic types are not affected.
Both denial of service vulnerabilities require only a single content service
to be active on the Cisco CSG2 and can be exploited via crafted TCP packets.
A three-way handshake is not required to exploit either of these
vulnerabilities. The vulnerabilities are triggered by TCP traffic that
transits the Cisco CSG2.
The service policy bypass vulnerability is documented in Cisco Bug ID
CSCtk35917 and has been assigned CVE ID CVE-2011-0348.
The denial of service bugs are documented in Cisco Bug ID CSCth17178 and
Cisco Bug ID CSCth41891 and have been assigned CVE IDs CVE-2011-0349 and
CVE-2011-0350 respectively.
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
* CSCtk35917 ("Service Policy Bypass Vulnerability")
CVSS Base Score - 6.4
Access Vector - Network
Access Complexity - Low
Authentication - None
Confidentiality Impact - Partial
Integrity Impact - Partial
Availability Impact - None
CVSS Temporal Score - 5.3
Exploitability - Functional
Remediation Level - Official-Fix
Report Confidence - Confirmed
* CSCth41891/CSCth17178 ("Crafted TCP packet causes CSG2 to restart")
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 the service policy bypass can allow customers to
obtain access to sites that would normally be accounted and billed according
to the billing policy without the billing policy being engaged.
Additionally, customers could gain access to URLs that are configured in the
Cisco CSG2 to be explicitly denied.
Successful exploitation of either denial of service vulnerability could
result in the Cisco CSG2 reloading or potentially hanging. Due to Cisco Bug
ID CSCtg50821, the Cisco CSG2 may not automatically recover and may require
a manual reload of the SAMI card by issuing the "hw-module module <x> reset"
CLI command from the switch.
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 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 | Availability of Repaired Releases |
| Release | |
|------------+--------------------------------------------------|
| Affected | |
| 12.x-Based | First Fixed Release |
| Releases | |
|------------+--------------------------------------------------|
| 12.0 - | 12.0 through 12.3 based releases are not |
| 12.3 | affected |
|------------+--------------------------------------------------|
| Affected | First Fixed Release |
| 12.4-Based |--------------------------------------------------|
| Releases | DoS | Service Policy Bypass |
| | Vulnerabilities | Vulnerability |
|------------+------------------+-------------------------------|
| | All 12.4(11)MD | |
| | releases are not | All 12.4(11)MD releases are |
| | affected. | affected. Migrate to a fixed |
| | | release. |
| | All 12.4(15)MD | |
| | releases are not | All 12.4(15)MD releases are |
| | affected. | affected. Migrate to a fixed |
| | | release. |
| | All 12.4(22)MD | |
| 12.4MD | releases are not | All 12.4(22)MD releases are |
| | affected. | affected. Migrate to a fixed |
| | | release. |
| | Releases prior | |
| | to 12.4(24)MD1 | All 12.4(24)MD releases prior |
| | are not | to 12.4(24)MD3 are affected. |
| | affected. | |
| | | First fixed in 12.4(24)MD3 |
| | First fixed in | |
| | 12.4(24)MD2 | |
|------------+------------------+-------------------------------|
| | | All 12.4(22)MDA releases |
| | | prior to 12.4(22)MDA5 are |
| | | affected. First fixed in 12.4 |
| | No releases | (22)MDA5 |
| 12.4MDA | affected. | |
| | | All 12.4(24)MDA releases |
| | | prior to 12.4(24)MDA3 are |
| | | affected. First fixed in 12.4 |
| | | (24)MDA3 |
|------------+--------------------------------------------------|
| Affected | |
| 15.X-Based | First Fixed Release |
| Releases | |
|------------+--------------------------------------------------|
| 15.0 - | 15.0 through 15.1 based releases are not |
| 15.1 | affected |
+---------------------------------------------------------------+
Cisco IOS Software for the CSG2 is located on Cisco Software Download center
at the following location: Cisco Interfaces and Modules --> Cisco Services
Modules --> Cisco Service Application Module for IP.
Workarounds
===========
There are no workarounds for these vulnerabilities.
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/docs/general/warranty/English/EU1KEN_.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 at cisco.com or security-alert at 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 at 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 aware of public announcements of the service billing
bypass vulnerability on some external blog sites. However the Cisco PSIRT is
not aware of any malicious use of the vulnerabilities described in this
advisory.
These vulnerabilities were found by both internal testing and when handling
customer support calls.
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-20110126-csg2.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 at cisco.com
* first-bulletins at lists.first.org
* bugtraq at securityfocus.com
* vulnwatch at vulnwatch.org
* cisco at spot.colorado.edu
* cisco-nsp at puck.nether.net
* full-disclosure at lists.grok.org.uk
* comp.dcom.sys.cisco at 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 1.0 | 2011-January-26 | Initial 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.h
tml.
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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Copyright 2010-2011 Cisco Systems, Inc. All rights reserved.
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