CVE-2025-9016

Executive Summary

CVE-2025-9016 is a high-severity (CVSS 7.0) uncontrolled search path vulnerability (CWE-427) in the Mechrevo Control Center GX V2 software, specifically version 5.56.51.48. The flaw resides in the PowerShell Script Handler component, which processes commands from the file C:/Program Files/OEM/机械革命控制中心/AiStoneService/MyControlCenter/Command. An attacker with local access can exploit this by placing a malicious executable or script in a directory that appears earlier in the system’s search path than the intended legitimate file. When the vulnerable component attempts to execute a command, it may inadvertently load the attacker’s payload, leading to arbitrary code execution with the privileges of the Control Center service. The exploit has been publicly disclosed, and no official patch is currently available. This vulnerability is particularly concerning for enterprise environments where Mechrevo systems are deployed, as it allows privilege escalation from a low-privileged user to SYSTEM level.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a native Windows application vulnerability.

CVSS Breakdown & Threat Level

• CVSS Score: 7.0 (High)
• Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
• Attack Vector (AV): Local – The attacker must have physical or remote interactive access to the target system.
• Attack Complexity (AC): High – Successful exploitation requires precise knowledge of the search path order and the ability to place a malicious file in a specific location.
• Privileges Required (PR): Low – The attacker needs only standard user privileges.
• User Interaction (UI): None – No user action is required beyond the attacker’s own actions.
• Scope (S): Unchanged – The vulnerable component and the attacker’s code run within the same security authority.
• Confidentiality (C): High – Full read access to sensitive data is possible.
• Integrity (I): High – The attacker can modify system files and configurations.
• Exploitability: The exploit is public and considered difficult due to the high attack complexity, but the lack of a patch makes it a persistent threat.

Deep Dive & Mechanics

The vulnerability is a classic uncontrolled search path (also known as DLL hijacking or path interception) in the Mechrevo Control Center GX V2. The component AiStoneService (likely a background service) executes PowerShell commands from a specific file path. When the service invokes a command (e.g., powershell.exe -Command ...), it relies on the system’s PATH environment variable to locate executables or scripts. An attacker can place a malicious powershell.exe or a script with the same name in a directory that is searched before the legitimate system directory (e.g., C:\Windows\System32). Common hijackable locations include the user’s %TEMP% folder, the application’s own directory, or any directory writable by the user.

The attack flow:

1. The attacker gains local access to the target system (e.g., via a compromised user account).
2. The attacker identifies a writable directory that appears earlier in the PATH than C:\Windows\System32.
3. The attacker places a malicious executable or script (e.g., powershell.exe) in that directory.
4. When the Mechrevo Control Center service triggers a PowerShell command, the system loads the attacker’s malicious file instead of the legitimate one.
5. The malicious payload executes with the service’s privileges (likely SYSTEM), allowing full compromise.

The vulnerability is difficult to exploit because the attacker must know the exact command being executed and the search order, but the public disclosure provides sufficient details.

Vulnerable vs. Patched Code

Since no patch is available, we compare the vulnerable behavior to a hypothetical secure implementation.

Vulnerable Code (Conceptual):

# Inside AiStoneService, the service reads a command from a file and executes it
$command = Get-Content "C:/Program Files/OEM/机械革命控制中心/AiStoneService/MyControlCenter/Command"
Invoke-Expression $command

This code does not specify the full path to powershell.exe, relying on the system’s PATH.

Patched Code (Hypothetical):

# Secure implementation uses absolute path
$command = Get-Content "C:/Program Files/OEM/机械革命控制中心/AiStoneService/MyControlCenter/Command"
& "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -Command $command

The patched version hardcodes the full path to powershell.exe, preventing path interception.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• Local access to a Windows system with Mechrevo Control Center GX V2 5.56.51.48 installed.
• A writable directory that is in the PATH before C:\Windows\System32 (e.g., C:\Users\<username>\AppData\Local\Temp).

Exploit Steps:

1. Create a malicious PowerShell script that performs privilege escalation (e.g., adds a new admin user).

   # malicious.ps1
   net user attacker P@ssw0rd! /add
   net localgroup Administrators attacker /add
   

2. Place the script in a hijackable location with a name that matches the expected command (e.g., powershell.exe).

   copy malicious.ps1 C:\Users\victim\AppData\Local\Temp\powershell.exe
   

3. Trigger the vulnerable component by interacting with the Mechrevo Control Center (e.g., opening the application or performing a specific action that invokes the PowerShell handler).
4. The service executes the malicious powershell.exe, which runs the script and creates the attacker account.

Alternative Exploit (DLL Hijacking): If the service loads a DLL without a full path, an attacker can place a malicious DLL in a writable directory. For example, if the service calls LoadLibrary("helper.dll"), the attacker places helper.dll in %TEMP%.

Blue Team (Defensive)

Detection:

• Monitor for unusual file creation in user-writable directories (e.g., %TEMP%, %APPDATA%) with names matching system executables (e.g., powershell.exe, cmd.exe).
• Enable PowerShell script block logging and transcription to capture malicious commands.
• Use Sysmon to log process creation events (Event ID 1) and look for powershell.exe launched from non-standard paths.

Prevention:

• Apply the principle of least privilege: ensure the Mechrevo Control Center service runs with minimal necessary rights.
• Use Windows Defender Application Control (WDAC) or AppLocker to block execution from user-writable directories.
• Modify the PATH environment variable to place system directories first and remove writable user directories.
• Monitor for changes to the PATH variable via registry auditing.

Indicators of Compromise (IOCs)

• File IOCs:

  • C:\Users\<username>\AppData\Local\Temp\powershell.exe (or other system executable names)
  • C:\Users\<username>\AppData\Local\Temp\helper.dll (or other DLL names)
  • Any file in a user-writable directory with the same name as a system binary.

• Process IOCs:

  • powershell.exe spawned from C:\Users\*\AppData\Local\Temp\ or other non-standard paths.
  • AiStoneService.exe (or related service) executing commands with unexpected parent processes.

• Network IOCs:

  • Outbound connections from powershell.exe to unknown IPs (if the payload downloads additional tools).

• Registry IOCs:

  • Changes to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment\Path (if the attacker modifies the system PATH).

Detection Engineering

YARA Rule

rule CVE_2025_9016_Mechrevo_Hijack {
    meta:
        description = "Detects malicious executables placed in user-writable directories targeting Mechrevo Control Center path hijacking"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-9016"
    strings:
        $s1 = "powershell.exe" ascii wide nocase
        $s2 = "cmd.exe" ascii wide nocase
        $s3 = "helper.dll" ascii wide nocase
        $path1 = "C:\\Users\\" ascii wide nocase
        $path2 = "\\AppData\\Local\\Temp\\" ascii wide nocase
    condition:
        (uint16(0) == 0x5A4D) and  // MZ header
        (($s1 or $s2 or $s3) and ($path1 and $path2))
}

Sigma Rule

title: Potential Mechrevo Control Center Path Hijacking
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects execution of system binaries from user-writable directories, indicating possible CVE-2025-9016 exploitation
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-9016
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\powershell.exe'
            - '\cmd.exe'
            - '\helper.dll'
        Image|contains:
            - '\AppData\Local\Temp\'
            - '\AppData\Roaming\'
    condition: selection
falsepositives:
    - Legitimate software installations that temporarily copy binaries to Temp
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (
    msg:"CVE-2025-9016 - Potential Mechrevo Control Center Exploit - Outbound from Hijacked Process";
    flow:to_server,established;
    content:"powershell.exe|20|"; http_user_agent;
    sid:1000001;
    rev:1;
    reference:cve,2025-9016;
    classtype:attempted-user;
    priority:1;
)

Remediation & Mitigation

Immediate Actions:

1. Isolate affected systems: If possible, disconnect Mechrevo systems from the network until a patch is applied.
2. Restrict local access: Ensure only authorized users have interactive logon rights to vulnerable machines.
3. Harden the PATH: Remove user-writable directories (e.g., %TEMP%, %APPDATA%) from the system PATH environment variable.
4. Monitor for exploitation: Deploy the provided YARA, Sigma, and Suricata rules to detect malicious activity.

Long-term Fixes:

• Vendor patch: Contact Mechrevo for an official update that hardcodes full paths to system binaries.
• Application whitelisting: Use AppLocker or WDAC to allow only trusted executables from specific directories.
• Service hardening: Run the Mechrevo Control Center service with a low-privileged account instead of SYSTEM.
• User education: Train users to report unusual behavior from the Control Center application.

Workaround:

• Manually edit the vulnerable script or configuration file to use absolute paths (e.g., replace powershell.exe with C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe). This may break functionality if the vendor updates the software.

Valters IT
DevSecOps & Cyber Threat Intelligence