-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

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

             AUSCERT External Security Bulletin Redistribution
                  ESB-2004.0488 -- Two iDEFENSE Bulletins:
             iDEFENSE Security Advisory 08.03.04a and 08.03.04b
  NGSEC StackDefender 1.10/2.0 Invalid Pointer Dereference Vulnerability
                               5 August 2004

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

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

Product:                NGSEC StackDefender 2.0
                        NGSEC StackDefender 1.10
Publisher:              iDEFENSE
Operating System:       Windows
Impact:                 Denial of Service
Access:                 Remote/Unauthenticated
CVE Names:              CAN-2004-0766 CAN-2004-0767

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

NGSEC StackDefender 1.10 Invalid Pointer Dereference Vulnerability

iDEFENSE Security Advisory 08.03.04a
www.idefense.com/application/poi/display?id=118&type=vulnerabilities
August 3, 2004

I. BACKGROUND

StackDefender is an IPS (Intrusion Prevention System), for Win32
platforms, that will deny shellcode from executing in User Stack and
Writable memory regions. StackDefender uses PAX technology for this
purpose.

II. DESCRIPTION

StackDefender offers protection by forcing executables run on a
protected system to load StackDefender dll's. This is done by hooking
the ZwOpenFile and ZwCreateFile functions. These two kernel API's are
responsible opening and creating files. The ZwOpenFile and ZwCreateFile
function declarations are as follows:

NTSTATUS  ZwCreateFile(
OUT PHANDLE  FileHandle, 
IN ACCESS_MASK  DesiredAccess, 
IN POBJECT_ATTRIBUTES  ObjectAttributes, 
OUT PIO_STATUS_BLOCK  IoStatusBlock, 
IN PLARGE_INTEGER  AllocationSize  OPTIONAL, 
IN ULONG  FileAttributes, 
IN ULONG  ShareAccess, 
IN ULONG  CreateDisposition, 
IN ULONG  CreateOptions, 
IN PVOID  EaBuffer  OPTIONAL, 
IN ULONG  EaLength);

NTSTATUS  ZwOpenFile(
OUT PHANDLE  FileHandle, 
IN ACCESS_MASK  DesiredAccess, 
IN POBJECT_ATTRIBUTES  ObjectAttributes, 
OUT PIO_STATUS_BLOCK  IoStatusBlock, 
IN ULONG  ShareAccess, 
IN ULONG  OpenOptions);

The problem specifically exists because StackDefender fails to verify
'ObjectAttribues' as a valid address prior accessing the structures
members.

III. ANALYSIS

Successful exploitation allows remote and local attackers to cause the
underlying system to crash. This is possible by specifying an invalid
address for 'ObjectAttribues'. Exploitation requires that an attacker
has an exploitation vector to the system that StackDefender attempts to
block.

IV. DETECTION

iDEFENSE has confirmed the existence of this vulnerability in
StackDefender 1.10.

V. WORKAROUND

iDEFENSE is currently unaware of any workarounds for this issue.

VI. VENDOR RESPONSE

The vendor has discontinued support for StackDefender 1.10 and has
recommended that all users still using StackDefender 1.10 upgrade to
StackDefender 2.10.

http://www.ngsec.com/downloads/stackdefender/StackDefender-2.10.exe

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2004-0767 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

07/10/2004   Vulnerability discovered by iDEFENSE
07/12/2004   Initial vendor contact
07/22/2004   Initial vendor response
08/03/2004   Public disclosure

IX. CREDIT

iDEFENSE Labs is credited with the discovery of this vulnerability.

Get paid for vulnerability research
http://www.idefense.com/poi/teams/vcp.jsp

X. LEGAL NOTICES

Copyright (c) 2004 iDEFENSE, Inc.

Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDEFENSE. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, please
email customerservice@idefense.com for permission.

Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on,
this information.

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

NGSEC StackDefender 2.0 Invalid Pointer Dereference Vulnerability

iDEFENSE Security Advisory 08.03.04b
www.idefense.com/application/poi/display?id=119&type=vulnerabilities
August 3, 2004

I. BACKGROUND

StackDefender is an IPS (Intrusion Prevention System), for Win32
platforms, that will deny shellcode from executing in User Stack and
Writable memory regions. StackDefender uses PAX technology for this
purpose.

II. DESCRIPTION

StackDefender offers protection by hooking ZwAllocateVirtualMemory and
ZwProtectVirtualMemory functions. These two kernel API's are responsible
for allocating and protecting memory. The ZwProtectVirtualMemory
function declaration is as follows:

   ZwProtectVirtualMemory(HANDLE ProcessHandle, PVOID *BaseAddress,
      PULONG ProtectSize, ULONG NewProtect, PULONG OldProtect);

The problem specifically exists because StackDefender fails to verify
'BaseAddress' as a valid address prior dereferencing it as a pointer.

III. ANALYSIS

Successful exploitation allows remote attackers to cause the underlying
system to crash. This is possible by specifying an invalid address for
'BaseAddress'. Exploitation requires that an attacker has an
exploitation vector to the system that StackDefender attempts to block.

IV. DETECTION

iDEFENSE has confirmed the existence of this vulnerability in the latest
version of StackDefender, version 2.0.

V. WORKAROUND

iDEFENSE is currently unaware of any workarounds for this issue.

VI. VENDOR FIX

The vendor has released the following patch fixing this issue:

http://www.ngsec.com/downloads/stackdefender/StackDefender-2.10.exe

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CAN-2004-0766 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

07/10/2004   Vulnerability discovered by iDEFENSE
07/12/2004   Initial vendor notification
07/22/2004   Initial vendor response
08/03/2004   Public disclosure

IX. CREDIT

Peter Silberman (iDEFENSE Labs) is credited with the discovery of this
vulnerability.

Get paid for vulnerability research
http://www.idefense.com/poi/teams/vcp.jsp

X. LEGAL NOTICES

Copyright (c) 2004 iDEFENSE, Inc.

Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDEFENSE. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, please
email customerservice@idefense.com for permission.

Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on,
this information.

- --------------------------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.

NOTE: Third Party Rights
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

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

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

iQCVAwUBQRGZJSh9+71yA2DNAQL8hQP+NKHJ1e0lWYZ2aT+TtfeWVCBifSoUWCxL
bQGYyMJJpGKe2pkjWfCnJvVNc7pjGOdevjABhBvHe2tO3K6J04sa4gL/RJDRs6aw
0qPiZQ25c8boh2uLsDOskyWGDXHC9CdResxCeAv8D59FGpNzLmpGRWxCDEOVsc3P
ZbLfl1fKqMQ=
=PnUQ
-----END PGP SIGNATURE-----