CVE-2026-73165: Advantech EKI-1242IEIMS RCE Vulnerability

CVE-2026-73165 Overview

CVE-2026-73165 is an OS Command Injection vulnerability [CWE-78] in the web management interface of the Advantech EKI-1242IEIMS industrial protocol gateway. The flaw exists in firmware version V1.06.01 and allows a remote authenticated attacker to execute arbitrary operating system commands as root through crafted request parameters. Nozomi Networks Labs identified and reported the issue to Advantech. Because the device operates in industrial control environments, successful exploitation grants full control of a gateway that bridges operational technology (OT) networks.

Critical Impact
An authenticated remote attacker can execute arbitrary OS commands as root on the Advantech EKI-1242IEIMS gateway, compromising confidentiality, integrity, and availability of the device and downstream OT assets.

Affected Products

Advantech EKI-1242IEIMS industrial protocol gateway
Firmware version V1.06.01
Web management interface component

Discovery Timeline

2026-09-16 - CVE-2026-73165 published to the National Vulnerability Database (NVD)
2026-09-16 - Last updated in NVD database
Vulnerability identified and disclosed by Nozomi Networks Labs to Advantech

Technical Details for CVE-2026-73165

Vulnerability Analysis

The vulnerability resides in the web management interface of the EKI-1242IEIMS. The interface accepts request parameters that are passed to an underlying operating system command without proper neutralization of shell metacharacters. An authenticated attacker who can reach the management interface over the network can inject shell commands into these parameters. The injected commands execute in the context of the root user because the web management service runs with elevated privileges on the device.

Exploitation compromises the entire gateway. Attackers can pivot into downstream serial or fieldbus networks, tamper with protocol conversion logic, and persist across reboots by modifying firmware-writable regions. The requirement for authentication limits opportunistic attacks, but industrial gateways frequently use shared or default credentials, reducing the practical barrier to entry.

Root Cause

The root cause is improper neutralization of special elements used in an OS command [CWE-78]. User-supplied HTTP request parameters flow into a command execution primitive (such as system(), popen(), or a shell invocation) without sanitization, escaping, or use of a parameterized API. Shell metacharacters including ;, |, &, backticks, and $() are interpreted by the underlying shell, allowing attackers to append arbitrary commands to the intended invocation.

Attack Vector

The attack vector is network-based against the device's web management interface. The attacker must first authenticate to the interface. Once authenticated, the attacker submits an HTTP request containing a parameter with an embedded command injection payload. The vulnerable handler concatenates the parameter into a shell command string and executes it, returning control of the device to the attacker. No user interaction is required beyond the attacker's own request.

No verified proof-of-concept code has been published. Refer to the Nozomi Networks CVE-2026-73165 Advisory and the Advantech Security Advisory EKI-1242IEIMS for further technical details.

Detection Methods for CVE-2026-73165

Indicators of Compromise

Unexpected outbound connections originating from the EKI-1242IEIMS gateway, particularly to unfamiliar IP addresses or ports
HTTP requests to the device management interface containing shell metacharacters such as ;, |, &&, `, or $() within URL parameters or POST bodies
New or modified processes running as root on the device that do not match the firmware baseline
Configuration changes to the gateway that were not initiated by authorized administrators

Detection Strategies

Inspect web server and management interface logs on the device for authenticated sessions submitting parameter values containing shell metacharacters
Deploy network intrusion detection signatures that flag command injection patterns in HTTP traffic destined for the gateway management interface
Baseline expected administrative traffic to the device and alert on deviations in source IP, request timing, or parameter content

Monitoring Recommendations

Forward device logs and network telemetry from OT segments to a centralized analytics platform for correlation with authentication events
Monitor authentication activity to the management interface for brute-force attempts, credential reuse, and logins from unexpected source addresses
Track firmware version and configuration state across all EKI-1242IEIMS devices to identify unauthorized modifications

How to Mitigate CVE-2026-73165

Immediate Actions Required

Apply the firmware update from Advantech as referenced in the Advantech Security Advisory EKI-1242IEIMS
Restrict access to the web management interface to a dedicated administrative VLAN or jump host
Rotate all administrative credentials on affected devices and remove any default or shared accounts
Audit recent authenticated sessions and configuration changes on the gateway for signs of exploitation

Patch Information

Advantech has published a security advisory for the EKI-1242IEIMS covering CVE-2026-73165. Consult the Advantech Security Advisory EKI-1242IEIMS for the fixed firmware release and upgrade instructions. Confirm the running firmware version after the update and validate that the management interface is no longer accepting unsafe input.

Workarounds

Place the gateway behind a firewall that blocks inbound HTTP and HTTPS access to the management interface from untrusted networks
Disable the web management interface when it is not actively required for administration
Enforce strong, unique administrative passwords and enable account lockout policies where supported by the firmware
Segment the OT network so that only authorized engineering workstations can reach industrial gateways

bash

# Configuration example: restrict management interface access with an upstream firewall
# Replace 10.10.20.0/24 with your authorized administrative subnet
# and 192.0.2.10 with the gateway's management IP
iptables -A FORWARD -s 10.10.20.0/24 -d 192.0.2.10 -p tcp --dport 443 -j ACCEPT
iptables -A FORWARD -d 192.0.2.10 -p tcp --dport 443 -j DROP
iptables -A FORWARD -d 192.0.2.10 -p tcp --dport 80 -j DROP