Core Security - CoreLabsAutodesk Maya Script Nodes Arbitrary Command Execution
Title: Autodesk Maya Script Nodes Arbitrary Command Execution
Advisory Id: CORE-2009-0910
Advisory URL: http://www.coresecurity.com/content/maya-arbitrary-command-execution
Date published: 2009-11-23
Date of last update: 2009-11-20
Vendors contacted: Autodesk
Release mode: User release
Autodesk Maya  is a high-end 3D computer graphics and 3D modeling software package.
Autodesk Maya offers so called "Script Nodes" as a way to program animation behavior using MEL (Maya Embedded Language) and the Python programming language. The Autodesk Maya file formats support embedding of scripting code as part of a scene package. Programs embeded in Maya files using scripting code are automatically executed upon opening of the file. An attacker can take control of a system where Maya is installed by sending a specially crafted scene package and enticing the user to open it. The scripting code will run with the privileges of the user running the Maya application.
The vendor did not provide fixes or workaround information.
You can prevent script nodes from executing when you open a file by following these steps:
This vulnerability was discovered and researched by Diego Juarez from Core Security Technologies during Bugweek 2009 .
The publication of this advisory was coordinated by Fernando Russ from Core Security Advisories Team.
Autodesk Maya offers so called "Script Nodes" as a way to program animation behavior using MEL (the proprietary Maya scripting language) and the Python programming language. Script nodes are saved on the
.ma file formats along with geometry and the rest of the scene data. By using files with embedded scripting code it is possible to execute arbitrary commands without any restriction and without requiring any user interaction after a user opened a malicious scene file.
The following steps work as Proof of Concept:
python("import os"); python("os.system('%SystemRoot%\\system32\\calc.exe')");
Save scene to a file with
.ma format. Next time you open the scene, calc.exe will be run. This same behavior can be obtained using pure MEL code.
 The author participated in Core Bugweek 2009 as member of the team "Gimbal Lock N Load".
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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.
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