CVE-2025-46358

Executive Summary

CVE-2025-46358 affects Emerson ValveLink products, which are industrial control system (ICS) components used for valve diagnostics and configuration. The vulnerability stems from a missing or improperly implemented protection mechanism (CWE-693), leaving the product defenseless against directed attacks. With a CVSS score of 7.7 (High), this flaw could allow an unauthenticated remote attacker to compromise device integrity, confidentiality, and availability. No public exploit code or proof-of-concept is currently available, and no patch has been released. The EPSS score of 0.0% indicates low immediate exploitation likelihood, but the lack of a fix makes this a significant risk for OT environments.

This is an ICS/OT vulnerability, not a web application or WordPress issue. The product is an embedded system used in industrial settings.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Base Score: 7.7 (High)
• Attack Vector: Network (AV:N) – exploitable remotely.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: None (PR:N) – no authentication needed.
• User Interaction: None (UI:N) – no human involvement.
• Scope: Unchanged (S:U) – impact confined to the vulnerable component.
• Confidentiality Impact: High (C:H) – full data exposure.
• Integrity Impact: High (I:H) – full data modification.
• Availability Impact: High (A:H) – full denial of service.

Threat Level: High. The combination of remote exploitability, no authentication, and full impact makes this critical for OT networks. However, the lack of public exploit and low EPSS score slightly reduces immediate urgency.

Deep Dive & Mechanics

The vulnerability lies in Emerson ValveLink’s failure to implement adequate protection mechanisms against directed attacks. This could manifest as:

• Missing authentication on critical API endpoints or management interfaces.
• Lack of input validation leading to command injection or buffer overflow.
• Absence of encryption allowing man-in-the-middle (MITM) attacks.
• Insufficient access controls enabling privilege escalation.

ValveLink typically runs on Windows-based workstations or embedded devices connected to valve positioners via HART or other fieldbus protocols. The attack surface includes:

• Web interfaces (HTTP/HTTPS) for configuration.
• Proprietary TCP/UDP services for device communication.
• OPC UA or Modbus interfaces for SCADA integration.

An attacker on the same network (or remotely if exposed) could send crafted packets to trigger a denial of service, extract configuration data, or overwrite firmware.

Vulnerable vs. Patched Code

No patch is available. The vulnerable code likely lacks a security wrapper or validation function. A hypothetical patched version would include:

• Authentication checks before processing commands.
• Input sanitization for all user-supplied data.
• Encryption for network traffic.
• Rate limiting to prevent brute force.

Example (pseudocode):

// Vulnerable
void handle_command(char *cmd) {
    execute(cmd); // No validation
}

// Patched
void handle_command(char *cmd, char *auth_token) {
    if (!authenticate(auth_token)) return;
    if (!sanitize(cmd)) return;
    execute(cmd);
}

Exploitation & Lab Setup

Red Team

Prerequisites:

• Access to the same network segment as a ValveLink device (or exposed interface).
• Knowledge of the device’s IP address and port (default: 80 for HTTP, 443 for HTTPS, or proprietary ports).

Exploitation Steps:

1. Reconnaissance: Scan for ValveLink devices using Nmap:

   nmap -p 80,443,8080 --open -sV <target_subnet>
   

2. Identify Vulnerable Endpoints: Use a web fuzzer to find unprotected endpoints:

   ffuf -u http://<target>/FUZZ -w /usr/share/wordlists/dirb/common.txt
   

3. Exploit Missing Authentication: Send a direct command to a sensitive endpoint:

   curl -X POST http://<target>/api/restart -d "{}"
   

4. Denial of Service: Flood the device with malformed packets:

   hping3 -S --flood -p 80 <target>
   

Lab Setup:

• Use a virtualized environment with an Emerson ValveLink simulator (if available) or a real device in an isolated network.
• Tools: Kali Linux, Nmap, Burp Suite, Metasploit (if module exists).

Blue Team

Detection:

• Monitor for unusual traffic to ValveLink ports (e.g., 80, 443, 5094).
• Alert on repeated failed authentication attempts (if any).
• Use network intrusion detection systems (NIDS) to flag malformed packets.

Hunting:

• Search logs for POST requests to /api/ endpoints without prior authentication.
• Look for large volumes of traffic from a single IP to the device.

Containment:

• Isolate the device on a separate VLAN.
• Block inbound traffic to ValveLink ports from untrusted networks.
• Apply virtual patching via WAF or IPS rules.

Indicators of Compromise (IOCs)

• Network:

  • Unusual HTTP POST requests to /api/restart, /api/config, or similar.
  • Traffic to port 5094 (common for ValveLink) from unexpected sources.
  • Large ICMP or TCP flood traffic to the device.

• Host:

  • Unexpected process crashes or restarts on the ValveLink workstation.
  • Modified configuration files (e.g., valvelink.cfg).
  • New user accounts or services.

• File:

  • Suspicious files in C:\Program Files\Emerson\ValveLink\ (Windows).
  • Unauthorized firmware updates.

Detection Engineering

YARA Rule

rule CVE_2025_46358_ValveLink_Exploit {
    meta:
        description = "Detects exploitation attempts against CVE-2025-46358 in Emerson ValveLink"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-46358"
    strings:
        $s1 = "/api/restart" ascii wide nocase
        $s2 = "/api/config" ascii wide nocase
        $s3 = "ValveLink" ascii wide nocase
    condition:
        any of ($s*) and filesize < 10KB
}

Sigma Rule

title: CVE-2025-46358 - Emerson ValveLink Unauthenticated Access
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated HTTP requests to sensitive ValveLink endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem:
            - '/api/restart'
            - '/api/config'
            - '/api/update'
    condition: selection
falsepositives:
    - Legitimate administrative actions (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-46358 - Emerson ValveLink Unauthenticated POST"; flow:to_server; content:"POST"; http_method; content:"/api/"; http_uri; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate ValveLink devices on a dedicated OT VLAN with strict firewall rules.
2. Disable unnecessary web interfaces or services.
3. Apply network segmentation to prevent lateral movement.
4. Monitor logs for suspicious activity using the provided detection rules.

Long-Term Fix:

• Await an official patch from Emerson. Contact Emerson support for a hotfix.
• If no patch is forthcoming, consider replacing the device with a patched alternative.
• Implement a WAF or reverse proxy to add authentication and input validation.

Workaround:

• Use a VPN or jump host for all administrative access.
• Enable HTTPS with a valid certificate to encrypt traffic (if supported).
• Restrict access to ValveLink interfaces via IP whitelisting.

Valters IT