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Cisco SN 5420 Storage Router vulnerable to DoS via HTTP request containing long headers

Vulnerability Note VU#968187

Original Release Date: 2002-01-14 | Last Revised: 2002-01-14


It is possible to cause a denial of service of the Cisco SN 5420 Storage Router by sending a HTTP request with a large header.


A vulnerability has been discovered in the Cisco SN 5420 Storage Router software versions 1.1(5) and earlier. By sending an HTTP request with a huge header , an intruder can cause a denial of service. Cisco has released an advisory to address this issue; it is available at


An attacker can cause a denial of service against the Cisco SN 5420 Storage Router.


This vulnerability is fixed in release 1.1(7) of the software. Please see Cisco's advisory for instructions on how to obtain the updated software for free. Cisco notes that version 1.1(6) of the software was never released.

Vendor Information


Cisco Affected

Updated:  January 10, 2002



Vendor Statement


Cisco Security Advisory: Multiple Vulnerabilities in Cisco SN 5420 Storage

Revision 1.0

For Public Release 2002 January 09 08:00 (UTC -0800)


Three vulnerabilities have been discovered in Cisco SN 5420 Storage
Router software releases up to and including 1.1(5). Two of the
vulnerabilities can cause a Denial-of-Service attack. The other allows
an access to the SN 5420 configuration if it has been previously saved
on the router.

There is no workaround for these vulnerabilities.

No other Cisco product is vulnerable.

This advisory is available at the

Affected Products

Cisco SN 5420 Storage Routers running software release up to and
including 1.1(5) are affected by the vulnerabilities. Please note that
1.1(6) version of the software was never released by Cisco.

To determine your software release, type show system at the command

No other Cisco products are affected.


It is possible to read stored configuration file from the
Storage Router without any authorization.

By sending a HTTP request with a huge headers it is possible to
crash the Storage Router.

It is possible to halt the Storage Router by sending a
fragmented packet over the Gigabit interface.


An unauthorized person may read the configuration of the
Storage Router. That may lead to unauthorized access of a
storage space.

By exploiting this vulnerability an attacker can cause

By exploiting this vulnerability an attacker can cause

Software Versions and Fixes

All three vulnerabilities are fixed in the release 1.1(7) of the
software, which is available on CCO. Please note that version 1.1(6)
of the software was never released by Cisco.

Obtaining Fixed Software

Cisco is offering free software upgrades to eliminate this
vulnerability for all affected customers.

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
Web site at

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 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:

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 "" or
"" for software upgrades.


It is possible to mitiagte this vulnerability by blocking
access on the network's edge and by using hard to guess names
for saved configuration.

There is no workaround for this vulnerability.

There is no workaround for this vulnerability.

Exploitation and Public Announcements

The Cisco PSIRT is not aware of any public announcements or malicious
use of the vulnerabilities described in this advisory.

These vulnerabilities were found internally during product testing.

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.


This notice will be posted on Cisco's Worldwide Web site at 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:

* (includes CERT/CC)
* 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 1.0 2002-Jan-09 08:00 GMT-0800 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 Web site at
This includes instructions for press inquiries regarding Cisco
security notices.

All Cisco Security Advisories are available at

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.

Version: PGP 6.5.3


Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

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Our thanks to Cisco for the information provided in their advisory.

This document was written by Jason Rafail.

Other Information

CVE IDs: None
Severity Metric: 5.63
Date Public: 2002-01-09
Date First Published: 2002-01-14
Date Last Updated: 2002-01-14 22:39 UTC
Document Revision: 12

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