Krzysztof Chudzik

**Name of the Vulnerable Software and Affected Versions** mH-DEVELOPER smart home module versions prior to 3.0.30 **Description** The software contains a hardcoded SSH public key located in the `/root/.ssh/authorized keys` file, which functions as a backdoor. The SSH daemon is configured to start automatically and permits root login via key authentication. An attacker possessing the corresponding private key can obtain a root shell, leading to full system compromise. This key persists after a factory reset and cannot be deleted without remounting the file system. The vendor stated this feature was intended solely for service purposes. **Recommendations** Update to version 3.0.30.

mH-DEVELOPER smart home module uses the same hard-coded SSH host keys on every device, with no per-device key generation. An attacker who extracts these keys from the firmware can set up a rogue SSH server that clients will trust without warning, enabling man-in-the-middle attacks and credential interception. This issue was fixed in version 3.0.30

mH-DEVELOPER smart home module does not verify tokens in its authorization middleware, leaving all HTTP API and WebSocket endpoints accessible without authentication. An unauthenticated attacker on the LAN can query these endpoints, access system information, and send raw control commands to manipulate building automation devices. This issue was fixed in version 3.0.30

mH-DEVELOPER smart home module does not load any firewall rules at startup. This leaves all listening services, including SSH, HTTP, WebSocket, and Node-RED, fully exposed on the LAN without access control. Any client on the same network can reach every service. This issue was fixed in version 3.0.30

mH-DEVELOPER smart home module sends its web interface and API traffic over unencrypted HTTP. Passwords, authentication tokens, and device commands are transmitted in cleartext. An attacker on the same network can intercept this traffic, steal credentials and tokens, and hijack sessions. This issue was fixed in version 3.0.30

**Name of the Vulnerable Software and Affected Versions** mH-DEVELOPER versions prior to 3.0.30 **Description** The smart home module uses an end-of-life and unsupported Debian 8 operating system and Node.js runtime v17.0.1 in its production firmware. This reliance on obsolete components exposes the device to known security flaws that no longer receive patches, potentially allowing an attacker to execute arbitrary code, access sensitive data, or trigger a denial of service. **Recommendations** Update to version 3.0.30.

mH-DEVELOPER smart home module is vulnerable to Denial of Service due to uncontrolled resource consumption. The Express bodyParser is configured with a 250 MB limit for JSON and URL-encoded request bodies. An authenticated attacker on the LAN can send large request bodies that exhausts buffers in RAM, causing out-of-memory conditions and crashing the fh-node process, resulting in denial of service. The successful attack depends on the current memory usage of the device which is not under full control of the attacker. Critically, due to CVE-2026-82930 all endpoints can be queried unauthenticated, so any user on LAN can perform this attack. This issue was fixed in version 3.0.30