CVE-2026-73166 Overview
CVE-2026-73166 is a code injection vulnerability [CWE-94] in the web management interface of the Advantech EKI-1242IEIMS industrial protocol gateway running firmware version V1.06.01. A remote authenticated attacker can execute arbitrary code on the device, including operating system commands as root. Nozomi Networks Labs identified and reported the flaw to Advantech.
Critical Impact
Authenticated attackers can execute arbitrary OS commands as root through the web management interface, resulting in full compromise of the affected industrial gateway.
Affected Products
- Advantech EKI-1242IEIMS industrial protocol gateway
- Firmware version V1.06.01
- Web management interface component
Discovery Timeline
- 2026-09-16 - CVE-2026-73166 published to the National Vulnerability Database (NVD)
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-73166
Vulnerability Analysis
The vulnerability resides in the web management interface of the Advantech EKI-1242IEIMS. The interface fails to properly control the generation of code from user-supplied input, allowing an authenticated attacker to inject and execute arbitrary code on the underlying operating system.
Because the web management process runs with elevated privileges, injected commands execute as root. This grants the attacker full control over the device, including access to configuration data, network traffic passing through the gateway, and the ability to pivot into connected operational technology (OT) networks.
The EKI-1242IEIMS is a modbus-to-IEC-61850 protocol gateway used in industrial automation. Successful exploitation places attackers directly on a bridging device between IT and OT segments, an especially sensitive position in industrial control system (ICS) environments.
Root Cause
The root cause is improper control of code generation [CWE-94] in the web management interface. User input flows into a code or command execution context without adequate sanitization, validation, or use of safe API alternatives.
Attack Vector
Exploitation requires network access to the web management interface and valid authentication credentials with sufficient privileges. Once authenticated, the attacker submits crafted input through the vulnerable interface parameter, causing the device to execute attacker-controlled code in the context of the root user. No user interaction is required beyond the attacker's own session.
Technical exploitation details have not been published. See the Nozomi Networks CVE-2026-73166 Advisory and the Advantech Security Advisory EKI-1242IEIMS for further information.
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Stop Exploit AttemptsDetection Methods for CVE-2026-73166
Indicators of Compromise
- Unexpected processes spawned by the web management service on the gateway.
- New or modified files in system directories following administrative sessions.
- Outbound connections from the EKI-1242IEIMS to untrusted hosts.
- Configuration changes or user account additions performed outside change windows.
Detection Strategies
- Enable and centrally collect web management interface access and audit logs from the gateway.
- Alert on authenticated sessions originating from unexpected source addresses or during off-hours.
- Correlate management-plane authentication events with subsequent configuration or firmware changes.
Monitoring Recommendations
- Deploy passive network monitoring on OT segments to baseline gateway behavior and flag deviations.
- Monitor for anomalous protocol traffic originating from the gateway toward IT or internet-facing hosts.
- Track privileged credential use for the device and rotate credentials on any suspicion of compromise.
How to Mitigate CVE-2026-73166
Immediate Actions Required
- Restrict network access to the web management interface to a dedicated management VLAN or jump host.
- Rotate all administrative credentials for the EKI-1242IEIMS and enforce strong, unique passwords.
- Review recent management interface logins and audit device configuration for unauthorized changes.
- Apply vendor-supplied firmware updates as soon as they are available for your deployment.
Patch Information
Refer to the Advantech Security Advisory EKI-1242IEIMS for the vendor's remediation guidance and fixed firmware information. Additional technical context is available in the Nozomi Networks CVE-2026-73166 Advisory.
Workarounds
- Isolate the gateway behind a firewall that permits management traffic only from authorized administrator workstations.
- Disable the web management interface when not in use, if the device supports alternative management channels.
- Apply the principle of least privilege to management accounts and remove unused or default accounts.
- Segment the gateway from general-purpose corporate networks to limit exposure to authenticated attackers.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
