CVE-2025-67038: Lantronix EDS5000 RCE Vulnerability

CVE-2025-67038 Overview

A critical OS command injection vulnerability has been discovered in Lantronix EDS5000 version 2.1.0.0R3. The HTTP RPC module in this industrial device server executes shell commands to write logs when user authentication fails. The vulnerability arises because the username parameter is directly concatenated with the shell command without any input sanitization, allowing attackers to inject arbitrary OS commands. These injected commands execute with root privileges, providing complete system compromise.

Critical Impact

Unauthenticated remote attackers can achieve root-level code execution on affected Lantronix EDS5000 devices by injecting malicious OS commands through the username parameter during failed authentication attempts.

Affected Products

• Lantronix EDS5000 version 2.1.0.0R3
• Lantronix EDS5000 firmware utilizing vulnerable HTTP RPC authentication logging

Discovery Timeline

• 2026-03-11 - CVE-2025-67038 published to NVD
• 2026-03-12 - Last updated in NVD database

Technical Details for CVE-2025-67038

Vulnerability Analysis

This command injection vulnerability (CWE-94: Improper Control of Generation of Code) exists in the authentication handling mechanism of the Lantronix EDS5000's HTTP RPC module. When a user's authentication attempt fails, the device logs this event by executing a shell command. The fundamental flaw is that the username value submitted by the user is directly incorporated into this shell command without proper sanitization or escaping.

Because the logging functionality runs with elevated privileges, any commands injected through the username field execute as the root user. This design allows an unauthenticated attacker to leverage intentionally failed login attempts as an attack vector. The vulnerability requires no prior authentication and can be exploited remotely over the network.

Industrial control system environments where these device servers are deployed are particularly at risk, as the Lantronix EDS5000 is commonly used to provide serial-to-Ethernet connectivity for industrial equipment. Compromise of this device could provide attackers with a foothold into operational technology (OT) networks.

Root Cause

The root cause is the lack of input validation and sanitization on the username parameter before it is used in shell command construction. The HTTP RPC module concatenates user-supplied input directly into a logging command string without escaping shell metacharacters. This allows attackers to break out of the intended command context and execute arbitrary commands by including shell operators such as semicolons, pipes, or backticks in the username field.

Attack Vector

The attack is conducted over the network via the HTTP RPC interface. An attacker crafts a malicious authentication request where the username contains OS command injection payloads. When the authentication fails, the device's logging mechanism executes the injected commands with root privileges. The attack requires no authentication and no user interaction, making it highly exploitable.

For example, an attacker could submit a username containing shell metacharacters followed by arbitrary commands. The device's logging code interprets these as additional shell instructions, executing them alongside the legitimate logging command. This could be used to establish reverse shells, exfiltrate sensitive configuration data, modify device settings, or pivot to other systems on the network.

Detection Methods for CVE-2025-67038

Indicators of Compromise

• Unusual authentication failure logs containing shell metacharacters (;, |, $(), backticks) in the username field
• Unexpected outbound network connections from EDS5000 devices
• Presence of unauthorized files or scripts in device filesystem
• Modified device configuration or unexpected firmware changes
• Process execution anomalies such as spawned shells from the HTTP service

Detection Strategies

• Monitor HTTP traffic to EDS5000 devices for authentication requests containing shell metacharacters in username parameters
• Implement network segmentation and monitor for unexpected traffic originating from industrial device servers
• Deploy network intrusion detection rules to identify command injection patterns in HTTP authentication payloads
• Review device logs for authentication failures with abnormal username entries

Monitoring Recommendations

• Enable comprehensive logging on network firewalls and IDS/IPS systems monitoring traffic to Lantronix devices
• Implement baseline monitoring for EDS5000 device behavior to detect anomalous activity
• Monitor for outbound connections from device servers to unexpected external IP addresses
• Alert on multiple rapid authentication failures from the same source IP

How to Mitigate CVE-2025-67038

Immediate Actions Required

• Isolate affected Lantronix EDS5000 devices from untrusted networks immediately
• Place EDS5000 devices behind firewalls and restrict access to authorized IP addresses only
• Disable external network access to the HTTP RPC interface if not required
• Implement network segmentation to prevent lateral movement from compromised devices
• Review device logs for signs of prior exploitation

Patch Information

Organizations should monitor Lantronix for security updates addressing this vulnerability. CISA has published an ICS advisory (ICSA-26-069-02) regarding this issue. Contact Lantronix support for firmware update availability and patching guidance. Additional product information is available at the Lantronix website and EDS5000 product page.

Workarounds

• Restrict network access to EDS5000 management interfaces using firewall rules and access control lists
• Implement VPN requirements for remote access to device management functions
• Deploy a web application firewall (WAF) in front of EDS5000 devices to filter malicious input patterns
• Disable the HTTP RPC interface if alternative management methods are available
• Consider placing vulnerable devices on isolated network segments with strict ingress/egress filtering

Network access to the vulnerable HTTP RPC interface should be restricted to trusted management hosts only until a patch is available. This can be accomplished through firewall configuration or network access control lists on upstream switching infrastructure.