Viessmann vulnerabilities

The Vitogate 300 web interface fails to enforce proper server-side authentication and relies on frontend-based authentication controls. This allows an attacker to simply modify HTML elements in the browser’s developer tools to bypass login restrictions. By removing specific UI elements, an attacker can reveal the hidden administration menu, giving them full control over the device.

An OS command injection vulnerability has been discovered in the Vitogate 300, which can be exploited by malicious users to compromise affected installations. Specifically, the `/cgi-bin/vitogate.cgi` endpoint is affected, when the `form` JSON parameter is set to `form-0-2`. The vulnerability stems from the fact that that function at offset 0x21c24 does not properly sanitize supplied input before interpolating it into a format string which gets passed to `popen()`. Consequently, an authenticated attacker is able to inject arbitrary OS commands and thus gain code execution on affected devices.