CVE-2024-1490: WAGO PLC OpenVPN RCE Vulnerability

CVE-2024-1490 Overview

CVE-2024-1490 is a command injection vulnerability affecting WAGO Programmable Logic Controllers (PLCs) through their web-based management interface. An authenticated remote attacker with high privileges can exploit the OpenVPN configuration functionality to execute arbitrary shell commands on the affected device. When user-defined scripts are permitted, the OpenVPN integration may allow an attacker to bypass intended security controls and gain full command execution capabilities on the underlying system.

Critical Impact

Successful exploitation allows authenticated attackers with administrative privileges to execute arbitrary commands on WAGO PLCs, potentially compromising industrial control systems and operational technology environments.

Affected Products

• WAGO PLCs with web-based management interface
• WAGO devices with OpenVPN configuration capability
• WAGO PLCs where user-defined scripts are permitted

Discovery Timeline

• 2026-04-09 - CVE CVE-2024-1490 published to NVD
• 2026-04-09 - Last updated in NVD database

Technical Details for CVE-2024-1490

Vulnerability Analysis

This vulnerability is classified as CWE-94 (Improper Control of Generation of Code), commonly known as Code Injection. The flaw exists in the web-based management interface of WAGO PLCs, specifically within the OpenVPN configuration handling mechanism. When an administrator configures OpenVPN settings through the web interface and user-defined scripts are enabled, the system fails to properly sanitize or validate input parameters before passing them to shell command execution routines.

The attack requires network access to the management interface and valid high-privilege credentials. Once authenticated, an attacker can craft malicious OpenVPN configuration parameters that contain embedded shell commands. When the system processes these configuration values, the unsanitized input is passed to a shell interpreter, resulting in arbitrary command execution with the privileges of the underlying service.

Root Cause

The root cause of CVE-2024-1490 stems from insufficient input validation and sanitization in the OpenVPN configuration processing logic. The web-based management interface accepts user-supplied configuration data and incorporates it into system operations without properly escaping or filtering shell metacharacters. When user-defined scripts are permitted in the OpenVPN configuration, this creates a direct path from user input to command execution, allowing injection of arbitrary shell commands.

Attack Vector

The attack is conducted remotely over the network through the web-based management interface. An attacker must first authenticate to the management interface with high-privilege credentials, such as an administrator account. Once authenticated, the attacker navigates to the OpenVPN configuration section and injects malicious shell commands within configuration parameters. These commands are then executed when the system processes the OpenVPN configuration, particularly when user-defined scripts are enabled.

The vulnerability requires the following conditions:

• Network access to the WAGO PLC management interface
• Valid credentials with high privileges (typically administrator)
• User-defined scripts enabled in OpenVPN configuration

For detailed technical information about this vulnerability, refer to the CERT@VDE Advisory VDE-2024-008.

Detection Methods for CVE-2024-1490

Indicators of Compromise

• Unexpected modifications to OpenVPN configuration files on WAGO PLCs
• Unusual process execution or shell activity originating from the web management service
• Authentication logs showing repeated access to OpenVPN configuration endpoints
• Network traffic anomalies indicating command and control communications from PLC devices

Detection Strategies

• Monitor web management interface logs for suspicious OpenVPN configuration changes
• Implement network intrusion detection rules to identify malformed configuration requests containing shell metacharacters
• Deploy industrial protocol monitoring to detect anomalous behavior from PLC devices
• Review authentication logs for unauthorized or unusual high-privilege account access

Monitoring Recommendations

• Enable comprehensive logging on WAGO PLC management interfaces
• Establish baseline behavior for OpenVPN configuration activities and alert on deviations
• Monitor outbound network connections from PLC devices for unauthorized communications
• Implement file integrity monitoring on OpenVPN configuration directories

How to Mitigate CVE-2024-1490

Immediate Actions Required

• Restrict network access to the web-based management interface using firewalls and network segmentation
• Disable user-defined scripts in OpenVPN configuration if not required for operations
• Review and strengthen authentication credentials for high-privilege accounts
• Audit existing OpenVPN configurations for potentially malicious entries
• Implement network monitoring for connections to and from affected WAGO PLCs

Patch Information

Organizations should consult the official WAGO security advisories and the CERT@VDE Advisory VDE-2024-008 for the latest patch information and firmware updates. Apply vendor-provided security updates as soon as they become available after testing in a non-production environment.

Workarounds

• Disable user-defined scripts functionality in OpenVPN configuration to prevent command injection
• Restrict management interface access to trusted networks and authorized IP addresses only
• Implement multi-factor authentication for management interface access where supported
• Place WAGO PLCs behind a demilitarized zone (DMZ) with strict ingress and egress filtering
• Consider using a VPN to access management interfaces rather than exposing them directly

# Network segmentation example - restrict management interface access
# Firewall rule to limit access to WAGO PLC management port (example)
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP