Summary
A critical authentication bypass in EWIO-2 allows unauthenticated attackers with network access to gain administrative control over the device. Once compromised, an attacker can change configurations, manipulate data, disrupt services, and potentially render the device non-functional.
Details
Impact
Due to these vulnerabilities an unauthenticated attacker can take over control of the device. The data integrity as well as the device availability could no longer be guaranteed.
Remediation
METZ CONNECT has released a new SW-Version 2.2.0. Install version 2.2.0 or later to remediate this vulnerability. Schedule the update at your next maintenance window. No workaround offers equivalent protection.
Product Description
Compact Ethernet I/O controller that bridges field signals to IP networks. It acts as a Modbus TCP or BACnet/IP server (plus Modbus RTU for field devices) and includes a web-based Node‑RED environment for simple logic, visualization, and data logging—ideal for building and industrial automation.
Vulnerabilities 5
-
Critical 9.8
Possible malfunction credential injection
The commissioning wizard on the affected devices does not validate if the device is already initialized. An unauthenticated remote attacker can construct POST requests to set root credentials.
-
Critical 9.8
Unauthenticated Local File Inclusion in php module
An unauthenticated remote attacker can execute arbitrary php files and gain full access of the affected devices.
-
High 8.8
Possible arbitrary file upload
A low privileged remote attacker can upload any file to an arbitrary location due to missing file check resulting in remote code execution.
-
High 8.8
Possible arbitrary code execution
A low privileged remote attacker can upload a new or overwrite an existing python script by using a path traversal of the target filename in php resulting in a remote code execution.
-
High 7.5
Improper access control via php endpoint
Due to webserver misconfiguration an unauthenticated remote attacker is able to read the source of php modules.
Revision history
-
#1.0.0
Initial revision
References
-
Energy-Controlling M-Bus No. 110930
https://www.metz-connect.com/home/produkte/c-logline/energie-controlling/datenlogger.6a.de.html?id=110930
-
Energy-Controlling BACnet / Modbus No. 110935
https://www.metz-connect.com/home/produkte/c-logline/energie-controlling/datenlogger.6a.de.html?id=110935
-
VDE-2025-097: METZ CONNECT: Config API – Authentication bypass leads to admin takeover in EWIO2 series - HTML
https://certvde.com/en/advisories/VDE-2025-097
-
Ethernet-IO BACnet / Modbus No. 110904
https://www.metz-connect.com/home/produkte/c-logline/i-o-komponenten/ethernet-i-os.69.de.html?id=110904
-
METZ CONNECT advisory overview at CERT@VDE
https://certvde.com/de/advisories/vendor/metz-connect/
-
ICS Advisory ICSA-25-322-05 - Web Version
https://www.cisa.gov/news-events/ics-advisories/icsa-25-322-05
-
Recommended Practices
https://www.cisa.gov/news-events/ics-alerts/ics-alert-10-301-01
-
Recommended Practices
https://www.cisa.gov/resources-tools/resources/ics-recommended-practices
-
Recommended Practices
https://www.cisa.gov/topics/industrial-control-systems
-
Recommended Practices
https://www.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf
-
Recommended Practices
https://www.cisa.gov/sites/default/files/publications/Cybersecurity_Best_Practices_for_Industrial_Control_Systems.pdf
-
Recommended Practices
https://www.cisa.gov/news-events/news/targeted-cyber-intrusion-detection-and-mitigation-strategies-update-b