-----BEGIN PGP SIGNED MESSAGE-----

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                  ESB-2004.0167 -- eEye Security Bulletin
    RealSecure/BlackICE Server Message Block (SMB) Processing Overflow
                             27 February 2004

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:                BlackICE PC Protection 3.6 cbr to ccb
                        BlackICE Server Protection 3.6 cbr to ccb
                        RealSecure Network 7.0, XPU 20.15 to 22.9
                        Real Secure Server Sensor 7.0 XPU 20.16 to 22.9
                        Proventia A Series XPU 20.15 to 22.9
                        Proventia G Series XPU 22.3 to 22.9
                        Proventia M Series XPU 1.3 to 1.7
                        RealSecure Desktop 7.0 eba to ebh
                        RealSecure Desktop 3.6 ebr to ecb
                        RealSecure Guard 3.6 ebr to ecb
                        RealSecure Sentry 3.6 ebr to ecb
Publisher:              eEye Digital Security
Operating System:       Windows Server 2003
                        Windows XP
                        Windows 2000
                        Windows NT
                        Windows ME
                        Windows 98
Impact:                 Administrator Compromise
Access Required:        Remote

- --------------------------BEGIN INCLUDED TEXT--------------------

RealSecure/BlackICE Server Message Block (SMB) Processing Overflow

Release Date:
February 26, 2004

Date Reported:
February 18, 2004

Severity:
High (Remote Code Execution)

Vendor:
Internet Security Systems

Software Affected:
RealSecure Network 7.0, XPU 20.15 through 22.9
Real Secure Server Sensor 7.0 XPU 20.16 through 22.9
Proventia A Series XPU 20.15 through 22.9
Proventia G Series XPU 22.3 through 22.9
Proventia M Series XPU 1.3 through 1.7
RealSecure Desktop 7.0 eba through ebh
RealSecure Desktop 3.6 ebr through ecb
RealSecure Guard 3.6 ebr through ecb
RealSecure Sentry 3.6 ebr through ecb
BlackICE PC Protection 3.6 cbr through ccb
BlackICE Server Protection 3.6 cbr through ccb

Description:
The RealSecure and BlackICE product lines from Internet Security Systems
offer host-based intrusion detection/prevention for large servers and
home networks. By design, these products attempt to identify and block
network attacks and intrusions.
 
eEye Digital Security has discovered a critical vulnerability in both
RealSecure and BlackICE. The vulnerability allows a remote attacker to
reliably overwrite heap memory with user-controlled data and execute
arbitrary code within the SYSTEM context. This attack will succeed with
BlackICE using its most paranoid settings.

This specific flaw exists within the component that handles the
processing of Server Message Block (SMB) packets. By issuing an
authentication request with a long username value, a direct heap
overwrite is triggered, and reliable code execution is then possible.

Technical Description:
An IDS/IPS system, by its very nature, requires that every packet
entering a system be parsed and dealt with accordingly. When BlackICE
and RealSecure encounter an SMB packet, the packet is analyzed,
processed and re-assembled. It is during this assembly phase that our
custom data is passed to an insufficiently sized heap-based buffer. All
processing is conducted before any authentication.

To successfully replicate this vulnerability only one SMB packet is
required. The client must issue an "SMB Session Setup AndX request".
This SMB is used to "set up" a session previously established with the
negotiate protocol. A primary function of this request is to perform a
user login to a remote host. As neither RealSecure nor BlackICE require
the state to be kept, no previous negotiation is required. To cause a
reliable heap overwrite, the AccountName parameter should contain a
string with a length of 300 bytes or greater.

Please refer to the SNIA Common Internet File System Technical Reference
(http://www.snia.org/tech_activities/CIFS/CIFS-TR-1p00_FINAL.pdf) for
detailed information on the required packet structures.

In the end, this vulnerability equates to a textbook heap overwrite
vulnerability, and code execution is effortless.

Protection:
Retina Network Security Scanner has been updated to identify this
vulnerability.

Vendor Status:
ISS have released patches for these issues. The patches are available
at:
http://www.iss.net/download/

Credit:
Barnaby Jack

Related Links:
Retina Network Security Scanner - Free 15 Day Trial
http://www.eeye.com/html/Products/Retina/index.html

Greetings:
Cathy, The Filthy Few (we'll make up for it in July), and, of course --
all of the eEye massive.

Copyright (c) 1998-2004 eEye Digital Security
Permission is hereby granted for the redistribution of this alert
electronically. It is not to be edited in any way without express
consent of eEye. If you wish to reprint the whole or any part of this
alert in any other medium excluding electronic medium, please e-mail
alert@eEye.com for permission.

Disclaimer
The information within this paper may change without notice. Use of this
information constitutes acceptance for use in an AS IS condition. There
are NO warranties with regard to this information. In no event shall the
author be liable for any damages whatsoever arising out of or in
connection with the use or spread of this information. Any use of this
information is at the user's own risk.

Feedback
Please send suggestions, updates, and comments to:

eEye Digital Security
http://www.eEye.com
info@eEye.com

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        http://www.auscert.org.au/render.html?cid=1980

If you believe that your computer system has been compromised or attacked in 
any way, we encourage you to let us know by completing the secure National IT 
Incident Reporting Form at:

        http://www.auscert.org.au/render.html?it=3192

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business 
                hours which are GMT+10:00 (AEST).  On call after hours 
                for member emergencies only.
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967

iQCVAwUBQD7mVyh9+71yA2DNAQEvsAQAnsCG+4BY/Yu1CHBcOS5F6pD1XIq4Fby3
YePZ4eP+WiU9YtjATA9kmQimo+Mtuc2kLajCn+t7r8ziqkiG4OEj8AK7wI9PQw3E
aNoN4iQHmLH+9dRPzvRbRdoHQdQby+FgRCrrKdyfJchWxIPhAkx/39XAF+S8Rw7U
S4d6RJcMzwQ=
=EoN1
-----END PGP SIGNATURE-----