Date: Tue, 9 Apr 2002 09:00:00 -0800 (PDT)
From: Cisco Systems Product Security Incident Response Team <psirt@cisco.com.>
To: [email protected]Subject: Cisco Security Advisory: Aironet Telnet Vulnerability
Cc: [email protected]
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Cisco Security Advisory: Aironet Telnet Vulnerability
Revision 1.0
For Public Release 2002 April 09 16:00 (UTC +0000)
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Please provide your feedback on this document.
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Contents
========
Summary
Affected Products
Details
Impact
Software Versions and Fixes
Obtaining Fixed Software
Workarounds
Exploitation and Public Announcements
Status of This Notice
Distribution
Revision History
Cisco Security Procedures
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Summary
=======
It is possible to cause a denial-of-service attack if Cisco Aironet
products have Telnet access enabled. Telnet access is the only requirement
for such an attack; there are no additional conditions.
The workaround for this vulnerability is to disable Telnet access.
No other Cisco product is vulnerable.
This advisory is available at
http://www.cisco.com/warp/public/707/Aironet-Telnet.shtml.
Affected Products
=================
All releases up to, but excluding, 11.21 are vulnerable. The following
hardware products are affected.
* Cisco Aironet Access Point 340 and 350
* Cisco Aironet Bridge 350
Products not affected are:
* Cisco Aironet Bridge 340
* Cisco Aironet 4800 Series
* Cisco Aironet 4500 Series and 3500 Series
* Cisco Aironet 3100 Series
No other Cisco products are affected.
Details
=======
This vulnerability is documented as Cisco Bug ID CSCdw81244.
It is possible to cause Cisco Aironet products to reboot if Telnet access
is enabled and a password is required for authorization. This can be
accomplished by providing an invalid username and password. This
vulnerability cannot be triggered via the web interface.
Impact
======
By repeatedly exploiting this vulnerability an attacker can cause denial of
service.
Software Versions and Fixes
This vulnerability is fixed in release 11.21, which is available now.
Obtaining Fixed Software
Cisco is offering free software upgrades to remedy this vulnerability for
all affected customers. Customers may only install and expect support for
the feature sets they have purchased.
Customers with service contracts should obtain upgraded software through
their regular update channels to any software release containing the
feature sets they have purchased. For most customers, this means that
upgrades should be obtained through the Software Center on Cisco's
Worldwide Web site at http://www.cisco.com.
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 assistance with the upgrade, which should be free
of charge.
Customers who purchased directly 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 obtain fixed software by contacting the Cisco Technical
Assistance Center (TAC).
Cisco 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: [email protected]
See 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.
Please 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.
Please do not contact either "[email protected]" or
"[email protected]" for software upgrades.
Workarounds
===========
The workaround is to disable Telnet access. You can accomplish this by
following the link, via the web interface, path to reach the Console/Telnet
Setup page:
1. On the Summary Status page, click Setup.
2. On the Setup page, click Console/Telnet in the Services section of the
page.
3. On that page, click on the radio button for Disable Telnet.
Note: You must use the web interface or be connected on the console since
you will be unable to save your changes if you are using Telnet. After
disabling Telnet, your Telnet session will be terminated.
Exploitation and Public Announcements
This issue was reported to Cisco by a customer. Cisco PSIRT is not aware of
any malicious exploitation or public discussion of this vulnerability.
Status of This Notice: FINAL
This is a final notice. Although Cisco cannot guarantee the accuracy of all
statements in this notice, all of the facts have been checked to the best
of our ability. Cisco does not anticipate issuing updated versions of this
notice unless there is some material change in the facts. Should there be a
significant change in the facts, Cisco may update this notice.
A standalone copy or paraphrase of the text of this security advisory that
omits the distribution URL in the following section is an uncontrolled
copy, and may lack important information or contain factual errors.
Distribution
============
This notice will be posted on Cisco's Worldwide Web site at
http://www.cisco.com/warp/public/707/Aironet-Telnet.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:
* [email protected]
* [email protected]
* [email protected] (includes CERT/CC)
* [email protected]
* comp.dcom.sys.cisco
* [email protected]
* Various internal Cisco mailing lists
Future updates of this notice, if any, will be placed on Cisco's Worldwide
Web server, but may or may not be actively announced on mailing lists or
newsgroups. Users concerned about this problem are encouraged to check the
URL given above for any updates.
Revision History
================
Revision 2002-April-09 Initial Public
Number 1.0 16:00 UTC +0000 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
Web site at
http://www.cisco.com/warp/public/707/sec_incident_response.shtml. 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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This notice is Copyright 2002 by Cisco Systems, Inc. This notice may be
redistributed freely after the release date given at the top of the text,
provided that redistributed copies are complete and unmodified, and include
all date and version information.
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