[c-nsp] Cisco Security Advisory: Default Passwords in NetFlow Collection Engine

Cisco Systems Product Security Incident Response Team psirt at cisco.com
Wed Apr 25 12:01:26 EDT 2007


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Cisco Security Advisory: Default Passwords in NetFlow Collection Engine

Advisory ID: cisco-sa-20070425-nfc

http://www.cisco.com/warp/public/707/cisco-sa-20070425-nfc.shtml

Revision 1.0

For Public Release 2007 April 25 1600 UTC (GMT)

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Summary
=======

Versions of Cisco Network Services (CNS) NetFlow Collection Engine (NFC)
prior to 6.0 create and use default accounts with identical usernames
and passwords. An attacker with knowledge of these accounts can modify
the application configuration and, in certain instances, gain user
access to the host operating system.

The upgrade to NFC version 6.0 is not a free upgrade. This default
password issue does not require a software upgrade and can be changed
by a configuration command for all affected customers. The workaround
detailed in this document demonstrates how to change the passwords in 5.0.

This advisory is posted at 
http://www.cisco.com/warp/public/707/cisco-sa-20070425-nfc.shtml.

Affected Products
=================

Vulnerable Products
+------------------

This vulnerability affects Cisco NetFlow Collection Engine running
software versions prior to 6.0.0. The software version of the Cisco
NetFlow Collection Engine can be determined by either logging into
the web-based user interface (UI) or using the "show-tech" parameter of
the nfcollector command from the host operating system. For customers
running version 6.0 or later, the nfcollector command uses the version
parameter to determine the software level.

Users can determine the NFC version by using a web browser to navigate
to http://<nfc-hostname>:8080/nfc in a web browser and selecting "About"
in the upper left-hand corner. The browser displays the NFC version in a
new window.

The NFC version can be determined from the host operating system
by using the show-tech parameter of the "/opt/CSCOnfc/nfcollector"
command. On systems running NFC version 5.0.3, the output from
"/opt/CSCOnfc/bin/nfcollector show-tech" should display a result similar
to the following:

   $ /opt/CSCOnfc/nfcollector show-tech

   ********** pkginfo/swlist **********
   Name        : CSCOnfc                      Relocations: /opt/CSCOnfc
   Version     : 5.0.3                             Vendor: Cisco Systems, Inc
   Release     : 2                             Build Date: Wed 06 Sep 2006 11:19:59 AM EDT
   Install Date: Mon 12 Feb 2007 04:26:54 PM EST      Build Host: nfc-hpux.cisco.com
   Group       : Applications/Network          Source RPM: CSCOnfc-5.0.3-2.src.rpm
   Size        : 109385602                        License: Copyright (c) 2002-2003 by Cisco Systems, Inc.
   Signature   : (none)
   URL         : http://www.cisco.com
   Summary     : Cisco NetFlow Collector
   Description :
   Cisco CNS NetFlow Collection Engine receives, filters, and aggregates NetFlow
    traffic data generated by Cisco routers and switches.


Products Confirmed Not Vulnerable
+--------------------------------

No other Cisco products are known to be vulnerable to the issues described in
this advisory.

Details
=======

Cisco CNS NetFlow Collection Engine is used to collect and monitor
NetFlow accounting data for devices that support NetFlow, such as
routers and switches. This data can be used to provide a network
baseline, against which irregular activities like denial of service
(DoS) attacks, worms, and other malicious activity can be more easily
detected.

NFC is installed on a supported UNIX platform. The installation creates
a default web based user account, nfcuser, which is required to perform
application maintenance, configuration, and troubleshooting with a
password of nfcuser. In versions prior to 6.0, the Linux installer will
also create a local user, also nfcuser, on the operating system with a
default password also identical to the username. If the user already
exists, the Linux installer will change the password to be the same as
the username.

This issue is documented in Cisco Bug ID CSCsh75038 

Vulnerability Scoring Details
+----------------------------

Cisco is providing scores for the vulnerabilities in this advisory based
Con the ommon Vulnerability Scoring System (CVSS).

Cisco will provide a base and temporal score. Customers can then
compute environmental scores to assist in determining the impact of the
vulnerability in individual networks.

Cisco PSIRT will set the bias in all cases to normal. Customers
are encouraged to apply the bias parameter when determining the
environmental impact of a particular vulnerability.

CVSS is a standards based scoring method that conveys vulnerability
severity and helps determine urgency and priority of response.

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 .


Cisco Bug IDs:

CSCsh75038 - Default password for nfcuser in NFC

CVSS Base Score: 5.6
    Access Vector: Remote
    Access Complexity: High
    Authentication: Not Required
    Confidentiality Impact: Partial
    Integrity Impact: Partial
    Availability Impact: Partial
    Impact Bias: Normal

CVSS Temporal Score: 5.1
    Exploitability: Functional
    Remediation Level: Workaround
    Report Confidence: Confirmed


Impact
======

Successful exploitation of the vulnerability may result in full
administrative control of the NetFlow Collection Engine and user-level
access to the host operating system.

Software Version 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.

Workarounds
===========

This issue has been addressed starting in release 6.0 by prompting the
user to change the password for the web based nfcuser account during the
application installation or during an upgrade to a version later than
6.0 as shown in the following example. This only applies to the web user
and password, on Linux hosts, the nfcuser on the host operating system
needs to be manually changed as shown at the end of the workarounds
section. Installations on Solaris have always required the local nfcuser
to be created before the installation and therefore only the web based
user account is affected by this advisory. NFC installations for version
6.0 and later on Solaris and Linux require the nfcuser account to be
created on the host operating system before the installer is run.

For all installations of NFC versions prior to 6.0, the web user can be
changed using the following procedure:

Edit the file authentication parameters stored in 
${NFC_DIR}/config/auth.config, as shown below. The nfc-user field can be 
changed and a strong password should be chosen for the nfc-password.

    NFC {
        com.cisco.nfc.collector.web.auth.SimpleLoginModule required nfc-user="nfcuser" nfc-password="nfcuser";
    };


Then as the nfcuser, stop and restart the NFC applications. This is done
using the nfcollector command, as shown in the following example:

    # su - nfcuser

    $ /opt/CSCOnfc/bin/nfcollector stop all
    nfcxml: Not Running
    collection: Not Running
    re: Not Running; autostart not configured
    web: Not Running

    $ /opt/CSCOnfc/bin/nfcollector start all
    This product contains cryptographic features and is subject to
    United States and local country laws governing import, export,
    transfer and use. Delivery of Cisco cryptographic products does
    not imply third-party authority to import, export, distribute
    or use encryption. Importers, exporters, distributors and users
    are responsible for compliance with U.S. and local country laws.

    By using this product you agree to comply with applicable laws
    and regulations. If you are unable to comply with U.S. and local
    laws, return this product immediately.

    A summary of U.S. laws governing Cisco cryptographic products may be
    found at: http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

    If you require further assistance please contact us by sending email
    to export at cisco.com.

    nfcxml: Running (pid: 6598)
    collection: Running (pid: 6606)
    re: Not Running; autostart not configured
    web: Running (pid: 6618)


Additionally, on Linux installations of NFC prior to version 6.0, use the
"passwd" command to change the nfcuser password, as shown in the following
example:

    # passwd nfcuser
    Changing password for user nfcuser.
    New UNIX password:
    Retype new UNIX password:
    passwd: all authentication tokens updated successfully.


Please note that the local user password does not have to match the
password of the web user account. Upgrading to version 6.0 will
automatically prompt the administrator for a new nfcuser password to
be used in the UI. The nfcuser password for the host operating system
should still be changed as described above.

Obtaining Fixed Software
========================

Cisco will not make free upgrade software available to address this
vulnerability for affected customers. The workaround described in this
document describes how to change the passwords in current releases of
the software. This advisory will be updated as fixed software becomes
available. 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/public/sw-license-agreement.html , or as otherwise
set forth at Cisco.com Downloads at 
http://www.cisco.com/public/sw-center/sw-usingswc.shtml.

Do not contact either "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 agreement 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 who do not hold a Cisco
service contract and customers who purchase through third-party vendors
but are unsuccessful at obtaining fixed software through their point
of sale should get their 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

Have your product serial number available and give the URL of this
notice as evidence of your 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 special 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.

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-20070425-nfc.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-teams at 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  | 2007-April-25   | 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.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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All contents are Copyright 2006-2007 Cisco Systems, Inc. All rights reserved.
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Updated: Apr 25, 2006                                        Document ID: 82078

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