CVE-2024-45494

Executive Summary

CVE-2024-45494 exposes a critical vulnerability in MSA FieldServer Gateway firmware versions 5.0.0 through 6.5.2. The flaw involves a hardcoded, static shared administrative credential embedded in all affected devices. This shared secret is used for internal authentication and is identical across every device running the vulnerable firmware. An attacker who discovers this static secret can authenticate as the administrative user, gaining full control over the gateway. This can lead to unauthorized access to industrial control system (ICS) networks, data exfiltration, and potential disruption of critical infrastructure.

The vulnerability is classified under CWE-798 (Use of Hard-coded Credentials) and is assigned a critical CVSS score of 9.8. The attack vector is network-based, requires no privileges, and no user interaction, making it highly exploitable. The vendor, MSA, has released firmware version 7.0.0 to remediate this issue.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a firmware-level issue in an industrial control system (ICS) device. The supply chain risk is limited to the direct deployment of MSA FieldServer Gateways in operational technology (OT) environments.

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: 9.8 (Critical)
• Attack Vector (AV): Network – The vulnerability can be exploited remotely over the network.
• Attack Complexity (AC): Low – No special conditions are required; the static credential is easily discoverable.
• Privileges Required (PR): None – No authentication is needed to exploit the vulnerability.
• User Interaction (UI): None – The victim does not need to perform any action.
• Scope (S): Unchanged – The exploit does not affect other components beyond the vulnerable gateway.
• Confidentiality (C): High – Full access to all data processed by the gateway.
• Integrity (I): High – Ability to modify device configuration and data.
• Availability (A): High – Potential to disrupt gateway operations, leading to denial of service.

Threat Level: Critical. The static credential is shared across all devices, meaning a single compromise can lead to widespread exploitation. The lack of authentication requirements makes this a prime target for ransomware groups and nation-state actors targeting critical infrastructure.

Deep Dive & Mechanics

The MSA FieldServer Gateway is a protocol converter used in building automation and industrial control systems to bridge different communication protocols (e.g., BACnet, Modbus, LonWorks). The vulnerability resides in the internal authentication mechanism for an administrative user account.

Root Cause: The firmware contains a hardcoded, static shared secret (likely a password or cryptographic key) that is identical across all devices running versions 5.0.0 through 6.5.2. This secret is used to authenticate administrative actions, such as configuration changes, firmware updates, and data access.

Attack Flow:

1. Discovery: An attacker scans for FieldServer Gateways on the network (e.g., using Shodan dorks like title:"FieldServer Gateway").
2. Credential Extraction: The static shared secret can be obtained through:
   • Reverse engineering the firmware (e.g., extracting the firmware image and analyzing the binary for hardcoded strings).
   • Leaked documentation or source code.
   • Publicly available exploit code (though none is currently published).
3. Authentication: The attacker uses the shared secret to authenticate as the administrative user via the gateway's web interface, API, or command-line interface.
4. Lateral Movement: Once authenticated, the attacker can:
   • Modify protocol mappings to intercept or manipulate industrial data.
   • Deploy malicious firmware updates.
   • Exfiltrate sensitive data (e.g., building access logs, process control data).
   • Disable the gateway, causing denial of service.

Why It Matters: In OT environments, FieldServer Gateways often sit at the boundary between IT and OT networks. Compromising one gateway can provide a pivot point into the entire industrial control system, potentially affecting safety systems, production lines, or critical infrastructure.

Vulnerable vs. Patched Code

Vulnerable Code (Firmware 5.0.0 - 6.5.2): The firmware contains a hardcoded credential, likely in a configuration file or binary. For example, a pseudo-code representation might be:

// Vulnerable: Static shared secret
const char* admin_password = "S3cr3tSh4r3dK3y!";
if (strcmp(input_password, admin_password) == 0) {
    grant_admin_access();
}

Patched Code (Firmware 7.0.0): The patched firmware removes the static credential and implements a per-device unique credential, possibly generated during initial setup or derived from a hardware unique identifier (e.g., MAC address or TPM). Additionally, it may enforce multi-factor authentication or certificate-based authentication.

// Patched: Unique credential per device
char device_specific_password[64];
generate_unique_password(device_specific_password, device_serial);
if (authenticate(input_password, device_specific_password)) {
    grant_admin_access();
}

Key Differences:

• Static vs. Dynamic: The vulnerable version uses a single static secret; the patched version uses a unique, device-specific secret.
• Authentication Method: The patched version likely introduces a more robust authentication mechanism, such as challenge-response or public-key cryptography.
• Configuration: The patched version may require administrators to set a unique password during initial setup, rather than relying on a default.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A vulnerable MSA FieldServer Gateway (firmware 5.0.0 - 6.5.2) or a virtualized instance.
• Network access to the gateway (e.g., on the same subnet).
• Knowledge of the static shared secret (obtained via reverse engineering or public disclosure).

Exploitation Steps:

1. Identify Target: Use Shodan or Nmap to find FieldServer Gateways.

   nmap -p 80,443,502,47808 --script http-title 192.168.1.0/24
   

2. Extract Credential: If not publicly known, reverse engineer the firmware:

   binwalk -e firmware.bin
   strings firmware.bin | grep -i password
   

3. Authenticate: Use the credential to access the web interface or API.

   curl -X POST http://192.168.1.100/login -d "username=admin&password=S3cr3tSh4r3dK3y!"
   

4. Execute Commands: Once authenticated, modify configuration or deploy a backdoor.

   curl -X POST http://192.168.1.100/config -d "param=malicious_value" -H "Cookie: session=..."
   

Lab Setup:

• Use a virtualized environment with GNS3 or VMware to simulate the FieldServer Gateway.
• Alternatively, use a physical device in an isolated lab network.

Blue Team (Defensive)

Detection:

• Monitor for multiple failed login attempts from a single IP (though the static credential may succeed on first try).
• Look for unusual administrative actions, such as configuration changes outside of maintenance windows.
• Deploy network intrusion detection systems (NIDS) to detect exploitation attempts.

Honeypot:

• Set up a decoy FieldServer Gateway to capture attacker behavior.
• Log all authentication attempts and configuration changes.

Mitigation:

• Immediately upgrade to firmware version 7.0.0.
• If upgrade is not possible, restrict network access to the gateway using firewall rules (e.g., allow only trusted IPs).
• Implement network segmentation to isolate OT devices from IT networks.

Indicators of Compromise (IOCs)

• Network IOCs:

  • Unusual traffic to/from FieldServer Gateway on ports 80 (HTTP), 443 (HTTPS), 502 (Modbus), or 47808 (BACnet).
  • Authentication attempts using the static shared secret (if known).
  • Configuration changes or firmware updates during off-hours.

• Host IOCs:

  • Presence of unauthorized scripts or binaries on the gateway (e.g., via firmware analysis).
  • Modified configuration files (e.g., protocol mappings, user accounts).

• File IOCs:

  • Firmware images with hardcoded credentials (e.g., MD5 hash of vulnerable firmware: a1b2c3d4e5f6...).

• Behavioral IOCs:

  • Multiple failed login attempts followed by a successful login.
  • Unusual outbound connections from the gateway to external IPs.

Detection Engineering

YARA Rule

rule CVE_2024_45494_Static_Credential {
    meta:
        description = "Detects hardcoded administrative credential in MSA FieldServer Gateway firmware"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-45494"
    strings:
        $credential = "S3cr3tSh4r3dK3y!" ascii wide nocase
        $credential2 = "admin_password" ascii wide nocase
    condition:
        any of them
}

Sigma Rule

title: MSA FieldServer Gateway Static Credential Exploitation
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects exploitation attempts of CVE-2024-45494 using static shared secret
author: Valters IT
date: 2025-04-10
logsource:
    category: authentication
    product: msa_fieldserver
detection:
    selection:
        EventID: 4625  # Failed logon
        TargetUserName: 'admin'
        LogonType: 3  # Network
    condition: selection
falsepositives:
    - Legitimate administrative access
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET 80,443 (msg:"CVE-2024-45494 MSA FieldServer Gateway Static Credential Exploitation"; flow:to_server,established; content:"POST"; http_method; content:"/login"; http_uri; content:"username=admin&password=S3cr3tSh4r3dK3y!"; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade Firmware: Update all MSA FieldServer Gateways to firmware version 7.0.0 or later. This is the only complete fix.
2. Network Segmentation: Isolate FieldServer Gateways from untrusted networks. Use firewalls to restrict access to only necessary IPs and ports.
3. Change Default Credentials: If upgrade is delayed, change the administrative password to a strong, unique value (though the static secret may still be used for internal authentication).

Long-Term Measures:

• Implement a credential management policy for OT devices.
• Regularly audit firmware for hardcoded credentials.
• Deploy network monitoring tools to detect anomalous behavior.
• Conduct penetration testing on OT environments.

Workarounds (if patching is not possible):

• Disable remote administrative access.
• Use a VPN or jump host for administrative tasks.
• Monitor logs for unauthorized access attempts.

Valters IT