CVE-2022-41657 is a serious vulnerability affecting Delta Electronics InfraSuite Device Master, versions 00.00.01a and prior. If you’re running this software, especially in critical infrastructure environments, you’ll want to understand this bug. Using simple and exclusive language, let’s break down what went wrong, how attackers can abuse it, and the practical risks—including a step-by-step look at how remote code execution can happen.

What Is InfraSuite Device Master?

Delta Electronics InfraSuite Device Master is software used for managing facility infrastructure—think industrial control systems that control things like smart power, cooling, and environmental monitoring. This is the kind of software you’d typically find in data centers or industrial plants.

The Core Problem: Unsafe Use of Serialized Data

The vulnerability happens because the application lets attacker-supplied data—already deserialized into memory—get used in file operations. Instead of validating this data, Methods in the program use it directly to create new files—possibly anywhere the application has permission.

Upload malicious scripts or executables

- Trigger remote code execution by targeting areas like startup folders, plugins, or configuration files

What the Code Looks Like

Here’s a simplified example of what the vulnerable logic could resemble. This is _not_ the original source code (since the product is closed), but a mock-up in pseudo-C# that mirrors the flaw:

// Example: Vulnerable method for deserializing and writing files
public void DeserializeAndWrite(byte[] inputData)
{
    // Deserialize object (attacker-controlled)
    FileObject fileObj = (FileObject)BinaryFormatter.Deserialize(inputData);

    // Write file directly using path from deserialized data
    File.WriteAllBytes(fileObj.FilePath, fileObj.FileContent);
}


Why is this dangerous?
If an attacker crafts inputData with a FilePath like C:\Windows\System32\malicious.exe, the application will happily create (or overwrite) that file with arbitrary content.

Send Malicious Serialized Data

The attacker sends data designed to deserialize into a file object with a path and payload content—think of a script or executable.

File Creation

The application writes the attacker’s file to disk. The attacker can choose the location and filename, within the permissions of the application.

Trigger Execution

- If the attacker places the payload in a startup folder or plugin directory, the application or system may execute their code on restart or next scheduled job.
  - Alternately, poisoning config files could corrupt the app’s flow to load arbitrary DLLs or scripts.

Example: Exploit Payload (Pseudo-code)

Suppose the app is running with admin rights. Here’s a minimal Python snippet that generates malicious serialized data if the file object serialization format is known.

import pickle

class FileObject:
    def __init__(self, FilePath, FileContent):
        self.FilePath = FilePath
        self.FileContent = FileContent

malicious_file = FileObject(
    "C:\\Windows\\System32\\calc.exe", 
    open("calc.exe", "rb").read()
)

exploit_payload = pickle.dumps(malicious_file)

# Send exploit_payload to the vulnerable InfraSuite endpoint.

*(Note: Actual serialization format may differ, adjust according to reverse engineering findings.)*

How Is This Remotely Exploitable?

- Network Exposure: Many Delta InfraSuite installations are networked for remote management. If the endpoint that deserializes file operations is not properly secured, attackers on the same network—or with VPN access—could exploit it by sending crafted requests.

- Privilege Level: The damage depends on the privilege the application runs with. Running as SYSTEM or Administrator means total control for the attacker.

Delta Electronics (Vendor Advisory):

Delta Electronics – InfraSuite Device Master Vulnerability

National Vulnerability Database (NVD):

CVE-2022-41657 Details

CISA Advisory:

CISA ICS Advisory: ICSA-22-294-07

Update or Patch Immediately

Delta Electronics released patches for newer versions. If possible, update InfraSuite Device Master beyond version 00.00.01a.

Conclusion

CVE-2022-41657 is a classic example of why validating and sanitizing user-controlled data is critical, especially before touching the file system. For operators of Delta Electronics InfraSuite, a quick patch could prevent an easy path to total compromise over your infrastructure controls.

Stay secure, and keep a close eye on how software deserializes and handles user-provided data!


*Note: All example code is for educational purposes only. Do not attempt exploitation on any system you do not own or have explicit permission to test.*

Timeline

Published on: 10/31/2022 20:15:00 UTC
Last modified on: 11/02/2022 14:04:00 UTC