CVE-2025-50109

Executive Summary

CVE-2025-50109 exposes a critical security flaw in Emerson ValveLink Products, where sensitive information is stored in cleartext within a resource accessible to another control sphere. This vulnerability, scoring 7.7 on the CVSS scale, allows an attacker with local access to the system to extract credentials, configuration data, or other secrets without authentication. The lack of encryption in storage violates fundamental security principles and can lead to lateral movement within industrial control system (ICS) environments. No public proof-of-concept (PoC) or exploit code is currently available, but the risk is elevated due to the sensitive nature of the data and the potential for privilege escalation.

CVSS Breakdown & Threat Level

• CVSS Score: 7.7 (High)
• Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
• Attack Vector (AV): Local – The attacker must have physical or logical access to the system.
• Attack Complexity (AC): Low – No special conditions or timing required.
• Privileges Required (PR): None – No authentication needed to access the resource.
• User Interaction (UI): None – No user action required.
• Scope (S): Changed – The vulnerable component impacts resources beyond its security scope.
• Confidentiality (C): High – Complete loss of confidentiality; all sensitive data exposed.
• Integrity (I): None – No impact on data integrity.
• Availability (A): None – No impact on system availability.

Threat Level: High. The vulnerability is easy to exploit locally and can expose critical secrets, enabling further attacks on the ICS network.

Deep Dive & Mechanics

The vulnerability resides in how Emerson ValveLink Products manage sensitive data. The software stores credentials, API keys, or configuration secrets in plaintext files or databases that are accessible to other processes or users within the same control sphere (e.g., a shared filesystem or network share). This violates the principle of least privilege and secure storage.

Root Cause: The application fails to encrypt sensitive data at rest. Instead of using secure storage mechanisms (e.g., Windows DPAPI, Linux keyrings, or encrypted configuration files), it writes data in cleartext to a location that is readable by other users or services.

Attack Scenario:

1. An attacker gains local access to the ValveLink host (e.g., via a compromised service account, physical access, or a separate vulnerability).
2. The attacker enumerates filesystem locations known to store ValveLink data (e.g., C:\ProgramData\Emerson\ValveLink\config.ini or /var/opt/emerson/valvelink/secrets).
3. The attacker reads the cleartext file, extracting credentials for database connections, SCADA interfaces, or other ICS components.
4. Using these credentials, the attacker moves laterally to other systems, potentially disrupting operations.

Vulnerable vs. Patched Code

Since no patch is available, the following illustrates the insecure pattern and a secure alternative.

Vulnerable Code (Python example):

import configparser

config = configparser.ConfigParser()
config['DEFAULT']['db_password'] = 'SuperSecret123'
with open('config.ini', 'w') as configfile:
    config.write(configfile)

Patched Code (Secure alternative):

import configparser
from cryptography.fernet import Fernet

# Generate and store key securely (e.g., in environment variable)
key = Fernet.generate_key()
cipher_suite = Fernet(key)

config = configparser.ConfigParser()
config['DEFAULT']['db_password'] = cipher_suite.encrypt(b'SuperSecret123').decode()
with open('config.enc', 'w') as configfile:
    config.write(configfile)

Explanation: The patched code encrypts the password before writing it to disk. The encryption key must be stored separately (e.g., in a hardware security module or environment variable) to prevent easy decryption.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

• Target: Windows Server 2019 with Emerson ValveLink installed (default configuration).
• Attacker: Kali Linux with access to the target's local network.

Steps:

1. Gain local access to the target (e.g., via RDP with stolen credentials or a separate exploit).
2. Identify ValveLink data directories:

   find / -type f -name "*.ini" 2>/dev/null | grep -i valvelink
   

3. Read the configuration file:

   cat /opt/emerson/valvelink/config.ini
   

4. Extract credentials and use them to authenticate to other systems (e.g., SQL Server, SCADA).

Exploit Code (None available): No public exploit exists; this is a manual data extraction vulnerability.

Blue Team (Defensive)

Detection:

• Monitor for unauthorized access to ValveLink configuration files.
• Use file integrity monitoring (FIM) to detect changes to sensitive files.
• Implement least privilege: restrict access to ValveLink directories to only the service account.

Hunting:

• Search for cleartext credentials in logs or configuration backups.
• Look for unusual processes reading ValveLink files (e.g., notepad.exe opening config.ini).

Indicators of Compromise (IOCs)

• File Paths:
  • C:\ProgramData\Emerson\ValveLink\config.ini
  • C:\Program Files\Emerson\ValveLink\secrets.txt
  • /var/opt/emerson/valvelink/credentials
• Registry Keys:
  • HKLM\SOFTWARE\Emerson\ValveLink\Credentials
• Network Connections: Unusual outbound connections from the ValveLink host to other ICS systems using extracted credentials.
• Process Anomalies: cmd.exe or powershell.exe reading ValveLink configuration files.

Detection Engineering

YARA Rule

rule CVE_2025_50109_ValveLink_Cleartext
{
    meta:
        description = "Detects cleartext storage of sensitive data in Emerson ValveLink files"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-50109"
    strings:
        $s1 = "password=" ascii wide nocase
        $s2 = "secret=" ascii wide nocase
        $s3 = "credentials" ascii wide nocase
        $s4 = "ValveLink" ascii wide nocase
    condition:
        (uint16(0) == 0x5A4D or uint32(0) == 0x464C457F) and
        (($s1 or $s2) and $s3 and $s4)
}

Sigma Rule

title: CVE-2025-50109 - Cleartext Credentials in ValveLink Configuration
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects access to ValveLink configuration files containing cleartext credentials
author: Valters IT
date: 2025-04-10
logsource:
    category: file_event
    product: windows
detection:
    selection:
        TargetFilename|contains:
            - 'ValveLink'
            - 'valvelink'
        TargetFilename|endswith:
            - '.ini'
            - '.txt'
            - '.cfg'
    condition: selection
falsepositives:
    - Legitimate administrative access
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-50109 - ValveLink Cleartext Credential Exfiltration"; flow:to_server,established; content:"password"; nocase; content:"ValveLink"; nocase; distance:0; within:100; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate ValveLink systems from untrusted networks.
2. Restrict local access to ValveLink hosts using strict ACLs.
3. Audit all ValveLink configuration files for cleartext secrets and rotate any exposed credentials.

Long-Term Fix:

• Apply vendor patch when available.
• Implement secure storage: use encrypted configuration files or a secrets management solution (e.g., HashiCorp Vault).
• Enforce least privilege: run ValveLink services under a dedicated account with minimal permissions.

Workaround:

• Manually encrypt sensitive data in configuration files using tools like certutil (Windows) or openssl (Linux).
• Monitor file access logs for unauthorized reads.

Valters IT Signature: This report was generated by Valters IT DevSecOps AI. For further analysis, contact Valters IT.