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

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

                       ESB-2007.0015 -- [UNIX/Linux]
               Multiple vendor X server privilege escalation
                    vulnerabilities via Render and DBE
                              10 January 2007

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

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

Product:              X.org 7.1 and prior
                      XFree86 4.6.0 and prior
Publisher:            iDefense
Operating System:     UNIX variants (UNIX, Linux, OSX)
Impact:               Root Compromise
Access:               Existing Account
CVE Names:            CVE-2006-6103 CVE-2006-6102 CVE-2006-6101

Original Bulletin:    
  http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=463
  http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=464
  http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=465

Comment: This bulletin contains three separate iDefense advisories for
         vulnerabilities in the Render and DBE extensions of X server
         implementations including X.org and XFree86.
         
         Each of the vulnerabilities allows an attacker who controls an
         existing user account to gain root privileges.

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

Multiple Vendor X Server Render Extension ProcRenderAddGlyphs Memory
Corruption Vulnerability

iDefense Security Advisory 01.09.07
http://labs.idefense.com/intelligence/vulnerabilities/
Jan 09, 2007

I. BACKGROUND

The X Window System is a graphical windowing system based on a
client/server model. More information about about The X Window system is
available at the following links.

http://en.wikipedia.org/wiki/X_Window_System

II. DESCRIPTION

Local exploitation of a memory corruption vulnerability in the
"ProcRenderAddGlyphs" function in the X.Org and XFree86 X server could
allow an attacker to execute arbitrary code with privileges of the X
server, typically root.

This vulnerability specifically lies within the Render extension.
Insufficient input validation exists when allocating memory for glyph
management data structures. By sending a specially crafted X protocol
request to the Render extension, an attacker can cause an exploitable
memory corruption condition.

III. ANALYSIS

Successful exploitation allows an attacker to execute arbitrary as the root
user. In order to exploit this vulnerability an attacker would require the
ability to send commands to an affected X server. This typically requires
access to the console, or access to the same account as a user who is on
the console. One method of gaining the required access would be to
remotely exploit a vulnerability in, for example, a graphical web browser.
This would then allow an attacker to exploit this vulnerability and elevate
their privileges to root.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in the X.Org
server version 7.1-1.1.0. Previous versions may also be affected.

V. WORKAROUND

Access to the vulnerable code can be prevented when the Render extension is
not built into the X binary. This can be accomplished by removing the entry
for the Render extension from your X server's configuration file, often
stored in /etc/X11 and named xorg.conf or XF86Config-4. To do this, remove
the following line from the 'Module' section:

Load "render"

This will prevent the Render extension from loading, which may affect the
appearance or operation of some applications.

VI. VENDOR RESPONSE

The X.Org foundation has addressed this vulnerability within version 7.2
RC3 of X.Org's X server. Additionally, patches have been made available
for older releases.

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2006-6101 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

12/04/2006  Initial vendor notification
12/05/2006  Initial vendor response
01/09/2007  Coordinated public disclosure

IX. CREDIT

This vulnerability was discovered by Sean Larsson, iDefense Labs.

Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php

Free tools, research and upcoming events
http://labs.idefense.com/

X. LEGAL NOTICES

Copyright © 2006 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 e-mail
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.


- --------------------------------------------------------------------------

Multiple Vendor X Server DBE Extension ProcDbeGetVisualInfo Memory
Corruption Vulnerability

iDefense Security Advisory 01.09.07
http://labs.idefense.com/intelligence/vulnerabilities/
Jan 09, 2007

I. BACKGROUND

The X Window System is a graphical windowing system based on a
client/server model. More information about about The X Window system is
available at the following link:

http://en.wikipedia.org/wiki/X_Window_System

II. DESCRIPTION

Local exploitation of a memory corruption vulnerability in the
"ProcDbeGetVisualInfo" function in the X.Org and XFree86 X server could
allow an attacker to execute arbitrary code with privileges of the X
server, typically root.

This vulnerability specifically lies within the DBE extension.
Insufficient input validation exists when allocating memory for data
structures. By sending a specially crafted X protocol request to the DBE
extension, an attacker can cause an exploitable memory corruption
condition.

III. ANALYSIS

Successful exploitation allows an attacker to execute arbitrary as the root
user. In order to exploit this vulnerability an attacker would require the
ability to send commands to an affected X server. This typically requires
access to the console, or access to the same account as a user who is on
the console. One method of gaining the required access would be to
remotely exploit a vulnerability in, for example, a graphical web browser.
This would then allow an attacker to exploit this vulnerability and elevate
their privileges to root.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in the X.Org
server version 7.1-1.1.0. Previous versions may also be affected.

V. WORKAROUND

Access to the vulnerable code can be prevented when the DBE extension is
not built into the X binary. This can be accomplished by removing the
entry for the DBE extension from your X server's configuration file, often
stored in /etc/X11 and named xorg.conf or XF86Config-4. To do this, remove
the following line from the 'Module' section:

Load "DBE"

This will prevent the render extension from loading, which may affect the
appearance or operation of some applications.

VI. VENDOR RESPONSE

The X.Org foundation has addressed this vulnerability within version 7.2
RC3 of X.Org's X server. Additionally, patches have been made available
for older releases.

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2006-6102 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

12/04/2006  Initial vendor notification
12/05/2006  Initial vendor response
01/09/2007  Coordinated public disclosure

IX. CREDIT

This vulnerability was discovered by Sean Larsson, iDefense Labs.

Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php

Free tools, research and upcoming events
http://labs.idefense.com/

X. LEGAL NOTICES

Copyright © 2006 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 e-mail
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.


- --------------------------------------------------------------------------

Multiple Vendor X Server DBE Extension ProcDbeSwapBuffers Memory
Corruption Vulnerability

iDefense Security Advisory 01.09.07
http://labs.idefense.com/intelligence/vulnerabilities/
Jan 09, 2007

I. BACKGROUND

The X Window System is a graphical windowing system based on a
client/server model. More information about about The X Window system is
available at the following link:

http://en.wikipedia.org/wiki/X_Window_System

II. DESCRIPTION

Local exploitation of a memory corruption vulnerability in the
"ProcDbeSwapBuffers" function in the X.Org and XFree86 X server could
allow an attacker to execute arbitrary code with privileges of the X
server, typically root.

This vulnerability specifically lies within the DBE extension.
Insufficient input validation exists when allocating memory for data
structures. By sending a specially crafted X protocol request to the DBE
extension, an attacker can cause an exploitable memory corruption
condition.

III. ANALYSIS

Successful exploitation allows an attacker to execute arbitrary as the root
user. In order to exploit this vulnerability an attacker would require the
ability to send commands to an affected X server. This typically requires
access to the console, or access to the same account as a user who is on
the console. One method of gaining the required access would be to
remotely exploit a vulnerability in, for example, a graphical web browser.
This would then allow an attacker to exploit this vulnerability and elevate
their privileges to root.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in the X.Org
server version 7.1-1.1.0. Previous versions may also be affected.

V. WORKAROUND

Access to the vulnerable code can be prevented when the DBE extension is
not built into the X binary. This can be accomplished by removing the
entry for the DBE extension from your X server's configuration file, often
stored in /etc/X11 and named xorg.conf or XF86Config-4. To do this, remove
the following line from the 'Module' section:

Load "DBE"

This will prevent the render extension from loading, which may affect the
appearance or operation of some applications.

VI. VENDOR RESPONSE

The X.Org foundation has addressed this vulnerability within version 7.2
RC3 of X.Org's X server. Additionally, patches have been made available
for older releases.

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2006-6103 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

12/04/2006  Initial vendor notification
12/05/2006  Initial vendor response
01/09/2007  Coordinated public disclosure

IX. CREDIT

This vulnerability was discovered by Sean Larsson, iDefense Labs.

Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php

Free tools, research and upcoming events
http://labs.idefense.com/

X. LEGAL NOTICES

Copyright © 2006 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 e-mail
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

iQCVAwUBRaSL5ih9+71yA2DNAQKdpQP/Y9NbFzrYtj4Um5BzLU0OQd65/2mvegOM
3gcummk2ZJYCrYrw7Ai6G0nNWoFhnDSVuY7L7qU0J/bgGBOuTSgwi90jPa01+M9Z
ITl0JSYnEHMfc565ir1z89GZCs9nC8fxmBWdzKjZJPgtVoq5vqUMOGLfyng0n+hw
8GKIEmWBJyo=
=ernQ
-----END PGP SIGNATURE-----