CVE-2025-0415: Web Interface NTP Settings RCE Vulnerability

CVE-2025-0415 Overview

CVE-2025-0415 is a critical command injection vulnerability affecting Moxa network devices. A remote attacker with web administrator privileges can exploit the device's web interface to execute arbitrary system commands through the NTP settings. Successful exploitation may result in the device entering an infinite reboot loop, leading to a total or partial denial of connectivity for downstream systems that rely on its network services.

Critical Impact

This command injection vulnerability allows authenticated administrators to execute arbitrary system commands, potentially causing permanent denial of service through infinite reboot loops and disrupting all dependent network infrastructure.

Affected Products

• Moxa network devices with web-based management interface
• Devices with vulnerable NTP configuration functionality
• Industrial network equipment running affected firmware versions

Discovery Timeline

• 2025-04-02 - CVE-2025-0415 published to NVD
• 2025-04-02 - Last updated in NVD database

Technical Details for CVE-2025-0415

Vulnerability Analysis

This vulnerability is classified as CWE-78 (Improper Neutralization of Special Elements used in an OS Command), commonly known as OS Command Injection. The flaw exists in the NTP settings configuration functionality of the device's web management interface.

When processing NTP server configuration parameters, the web interface fails to properly sanitize user-supplied input before passing it to underlying system commands. An attacker with administrative web access can inject malicious shell commands that execute with system-level privileges on the affected device.

The exploitation requires authenticated access with web administrator privileges, limiting the attack surface to scenarios where an attacker has already compromised administrator credentials or has legitimate administrative access but malicious intent. Despite this prerequisite, the potential impact is severe—complete system compromise and denial of service affecting all downstream network operations.

Root Cause

The root cause of CVE-2025-0415 lies in inadequate input validation and sanitization within the NTP configuration handler. The application directly incorporates user-supplied NTP server values into system command execution without proper escaping or validation. This allows shell metacharacters and command separators to be interpreted by the underlying operating system, enabling arbitrary command execution.

Attack Vector

The attack vector is network-based, requiring the attacker to have authenticated administrative access to the device's web management interface. The attack flow involves:

1. Authenticating to the device's web interface with administrator credentials
2. Navigating to the NTP configuration settings
3. Injecting malicious shell commands within NTP server input fields
4. Submitting the configuration, triggering command execution on the underlying system
5. Malicious commands execute with system privileges, potentially triggering reboot loops or other denial of service conditions

The vulnerability can be exploited remotely without user interaction once administrative access is obtained. The attacker can craft payloads that cause the device to enter an infinite reboot loop, effectively taking the device offline and disrupting all network services that depend on it.

Detection Methods for CVE-2025-0415

Indicators of Compromise

• Unexpected device reboots or boot loops without administrative action
• Anomalous NTP configuration values containing shell metacharacters (;, |, &, $(), backticks)
• Unusual system command execution patterns in device logs
• Unauthorized modifications to NTP settings

Detection Strategies

• Monitor web management interface access logs for suspicious NTP configuration changes
• Implement network-based detection rules for HTTP requests containing command injection patterns targeting NTP endpoints
• Alert on repeated device reboots within short time intervals
• Review authentication logs for compromised administrator accounts

Monitoring Recommendations

• Enable comprehensive logging on device web management interfaces
• Implement SIEM rules to correlate NTP configuration changes with subsequent system anomalies
• Monitor network traffic for signs of command injection attempts in HTTP POST data
• Establish baseline device behavior to detect deviation indicating exploitation

How to Mitigate CVE-2025-0415

Immediate Actions Required

• Review and restrict administrative access to affected Moxa devices
• Implement network segmentation to limit exposure of management interfaces
• Enable multi-factor authentication for administrative access where supported
• Audit NTP configuration settings for signs of tampering or malicious entries

Patch Information

Moxa has released a security advisory addressing this vulnerability. Administrators should consult the Moxa Security Advisory MPSA-259491 for specific patch information and affected product versions. Apply the latest firmware updates provided by Moxa to remediate this vulnerability.

Workarounds

• Restrict web management interface access to trusted networks only using firewall rules
• Disable web-based management if not required and use alternative management methods
• Implement strict access control lists (ACLs) limiting administrative access to specific IP addresses
• Consider placing management interfaces on isolated management VLANs

# Example firewall rule to restrict management interface access
# Restrict access to management port (typically 80/443) to trusted admin subnet only
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP