Acer LunchApp.APlunch ActiveX Control Command Execution Exploit Explained

What this paper is

This paper details a vulnerability in the Acer LunchApp.APlunch ActiveX control, allowing an attacker to execute arbitrary commands on a vulnerable system. The exploit leverages a method within the ActiveX control to run programs specified by the attacker.

Simple technical breakdown

ActiveX controls are small programs that run within a web browser, often used to add interactive features. This specific control, APlunch.APlunch, has a function called Run. When this Run function is called with specific arguments, it can be tricked into executing any command-line program. The exploit uses this by calling Run and telling it to execute calc.exe (the Windows Calculator).

Complete code and payload walkthrough

The provided source is a simple HTML file containing an ActiveX object and a JavaScript snippet.

<html>
<body>
<object classid="clsid:D9998BD0-7957-11D2-8FED-00606730D3AA" id="hahaha">
</object>
<script>
hahaha.Run("c", "\\windows\\system32\\calc.exe", "");
</script>
</html>
</body>

Let's break down each meaningful part:

<object classid="clsid:D9998BD0-7957-11D2-8FED-00606730D3AA" id="hahaha">:
- classid="clsid:D9998BD0-7957-11D2-8FED-00606730D3AA": This is the unique identifier (CLSID) for the vulnerable Acer LunchApp.APlunch ActiveX control. When a web page with this tag is loaded in a browser, the browser attempts to instantiate this control.
- id="hahaha": This assigns a JavaScript variable name (hahaha) to the instantiated ActiveX object. This allows the JavaScript code to interact with the control.
- Practical Purpose: This block tells the browser to load and initialize the vulnerable Acer ActiveX control.
<script>:
- This tag encloses JavaScript code that will be executed by the browser.
hahaha.Run("c", "\\windows\\system32\\calc.exe", "");:
- hahaha.Run(...): This is a call to the Run method of the APlunch.APlunch ActiveX control, which we've aliased as hahaha.
- "c": This is the first argument passed to the Run method. Based on typical command execution functions, this likely represents a command or a parameter related to execution. Its exact purpose within the Run method is not explicitly detailed in the provided snippet but is crucial for triggering the vulnerability.
- "\\windows\\system32\\calc.exe": This is the second argument. This is the path to the executable that the Run method is instructed to execute. In this case, it's the Windows Calculator. The double backslashes are often used in strings to escape a single backslash, ensuring the path is interpreted correctly.
- "": This is the third argument. It's an empty string, likely representing additional parameters for the executed command, or it might be unused in this specific exploit scenario.
- Practical Purpose: This line is the core of the exploit. It invokes the Run method of the vulnerable ActiveX control, passing it arguments that cause it to execute calc.exe. The vulnerability lies in how the Run method processes these arguments, allowing arbitrary command execution.

Mapping list:

classid="clsid:D9998BD0-7957-11D2-8FED-00606730D3AA" -> Instantiates the vulnerable Acer LunchApp.APlunch ActiveX control.
id="hahaha" -> Assigns a JavaScript alias to the ActiveX object for interaction.
hahaha.Run(...) -> Calls the vulnerable method within the ActiveX control.
"c" -> First parameter to Run, likely a command specifier.
"\\windows\\system32\\calc.exe" -> The executable to be run.
"" -> Third parameter to Run, potentially unused or for further arguments.

Shellcode/Payload:
There is no explicit shellcode or binary payload in the provided source. The "payload" here is the JavaScript code that calls the vulnerable ActiveX method, which in turn triggers the execution of calc.exe. The execution of calc.exe is the observable outcome.

Practical details for offensive operations teams

Required Access Level:
- Network Access: The target system must be able to access the malicious HTML file, typically via a web server.
- Browser Access: The target user must open the HTML file in a web browser that supports and has the vulnerable ActiveX control installed.
Lab Preconditions:
- Vulnerable System: A Windows machine with the Acer LunchApp.APlunch ActiveX control installed. This control was likely part of Acer system utilities. Identifying specific Acer models and OS versions that shipped with this control would be a prerequisite.
- Web Server: A simple HTTP server to host the malicious HTML file.
- Browser: Internet Explorer (or a compatible browser) on the target system.
Tooling Assumptions:
- Basic HTML/JavaScript Knowledge: To craft the exploit page.
- Web Server: Any standard web server (e.g., Python's http.server, Apache, Nginx).
- Vulnerability Scanner/Information Gathering: To identify systems with the vulnerable ActiveX control.
Execution Pitfalls:
- ActiveX Not Installed: The exploit will fail if the target system does not have the APlunch.APlunch ActiveX control installed.
- Browser Security Settings: Modern browsers have significantly restricted or disabled ActiveX support. Even older versions might have security settings that prevent ActiveX from running or executing arbitrary commands.
- Antivirus/Endpoint Detection: Antivirus software might detect the instantiation of known vulnerable ActiveX controls or the execution of calc.exe via this method.
- Control Registration: The ActiveX control needs to be properly registered on the target system for the clsid to be recognized.
- Path Variations: The exploit assumes calc.exe is located at \windows\system32\. While standard, variations in system configurations could exist.
Tradecraft Considerations:
- Delivery Mechanism: This exploit is typically delivered via a malicious website or an email attachment containing the HTML.
- Stealth: The exploit itself is relatively simple and relies on the presence of the vulnerable component. The primary stealth challenge is delivering the HTML page and ensuring the user visits it.
- Payload Customization: The calc.exe can be replaced with any other executable (e.g., a downloader, a reverse shell executable). The path might need adjustment based on target system knowledge.

Where this was used and when

Context: This exploit targets a specific ActiveX control bundled with Acer system utilities. Its primary use case would be in targeted attacks against users of Acer notebooks that shipped with this vulnerable software.
Approximate Years/Dates: Published in 2006. Exploits of this nature were common in the mid-2000s when ActiveX was widely used for web interactivity and security practices were less mature. It's likely this vulnerability existed and was potentially exploited in the years leading up to its publication.

Defensive lessons for modern teams

ActiveX is Legacy and Risky: Modern systems and browsers have largely deprecated or disabled ActiveX due to its inherent security risks. Organizations should ensure no legacy applications rely on ActiveX components.
Software Inventory and Patching: Maintain a comprehensive inventory of installed software, including system utilities and third-party components. Regularly patch or remove vulnerable software.
Browser Security Hardening: Configure browsers to disable or restrict ActiveX execution. Implement web filtering to block access to known malicious sites.
Endpoint Detection and Response (EDR): EDR solutions can monitor for suspicious process creation (like calc.exe being launched by an unexpected process) and unusual COM object instantiations.
Principle of Least Privilege: Ensure users run with standard user privileges, limiting the impact of command execution vulnerabilities.

ASCII visual (if applicable)

This exploit is a direct client-side interaction. An ASCII visual might not be strictly necessary for understanding the flow, but here's a simplified representation of the interaction:

+-----------------+     +-----------------------+     +---------------------+
| User's Browser  | --> | Malicious HTML Page   | --> | Acer LunchApp.APlunch |
| (IE)            |     | (Loads ActiveX)       |     | ActiveX Control       |
+-----------------+     +-----------------------+     +----------+----------+
                                                                 |
                                                                 | Calls Run()
                                                                 v
                                                        +---------------------+
                                                        | OS Command Execution|
                                                        | (e.g., calc.exe)    |
                                                        +---------------------+

Source references

Paper URL: https://www.exploit-db.com/papers/2866
Author: Tan Chew Keong
Published: 2006-11-30
Keywords: Windows, remote

Original Exploit-DB Content (Verbatim)

<!--
Author: Tan Chew Keong 
Site: http://vuln.sg/
Acer Notebook LunchApp.APlunch ActiveX Control Command Execution Exploit
-->

<html>
<body>
<object classid="clsid:D9998BD0-7957-11D2-8FED-00606730D3AA" id="hahaha">
</object>
<script>
hahaha.Run("c", "\\windows\\system32\\calc.exe", "");
</script>
</html>
</body>

# milw0rm.com [2006-11-30]

By exploitdb papers bot•November 30, 2006•

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