OTPulse

HMS Networks Ewon Flexy and Cosy

Low RiskCVSS 2.3ICS-CERT ICSA-20-254-03Sep 10, 2020
HMS Networks
Attack path
Attack VectorLocal
Auth RequiredHigh
ComplexityLow
User InteractionNone needed
Summary

HMS Networks Ewon Flexy and Cosy devices contain a vulnerability (CWE-942) that allows retrieval of limited confidential information. The vulnerability affects all versions before 14.1. Exploitation requires local console or physical access to the device and high privilege credentials. No public exploits are known, and the vulnerability is not remotely exploitable. HMS Networks recommends updating firmware to version 14.1 or later when available and implementing network segmentation and firewall controls.

What this means
What could happen
An attacker with local access to an Ewon device could read limited confidential information from memory or configuration. This is a low-risk local information disclosure that does not affect device operation or remote systems.
Who's at risk
Water utilities, municipal electric systems, and other industrial plants that use HMS Networks Ewon Flexy or Cosy remote access gateways for remote monitoring or device management. The risk is limited because exploitation requires local access and does not affect field devices or control logic.
How it could be exploited
An attacker must have physical or local console access to the device. They cannot exploit this vulnerability remotely. Local access would be needed to read sensitive data from the Ewon's memory or configuration storage.
Prerequisites
  • Physical or local console access to the Ewon device
  • High privilege level (administrative credentials or direct hardware access)
local access only, not remotely exploitablerequires high privilege credentialslow CVSS score (2.3)no public exploit availableno patch available from vendor
Exploitability
Unlikely to be exploited — EPSS score 0.0%
Affected products (1)
ProductAffected VersionsFix Status
Flexy and Cosy: All< 14.114.1+
Remediation & Mitigation
0/5
Do now
0/2
HARDENINGEnable and configure the built-in WAN firewall on all Ewon devices to restrict unauthorized access
HARDENINGDo not expose the WAN IP address of Ewon devices directly to the Internet; use the Talk2M cloud VPN solution for remote access instead
Schedule — requires maintenance window
0/1

Patching may require device reboot — plan for process interruption

HOTFIXUpdate Ewon Flexy and Cosy firmware to version 14.1 or later when available from HMS Networks
Long-term hardening
0/2
HARDENINGPlace Ewon devices behind a firewall and isolate them from the business network; minimize direct network exposure
HARDENINGRestrict physical access to Ewon devices to authorized personnel only
View full CISA ICS-CERT advisory
API: /api/v1/advisories/a7d890ca-4615-420e-b269-fa2efe31f4dc

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HMS Networks Ewon Flexy and Cosy | CVSS 2.3 - OTPulse