What’s Vulnerable › Vulnerabilities
CVE-2025-9495: Viessmann Vitogate 300 Authentication Bypass
- Severity: high (CVSS 8.7 v4.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-09-23 · updated 2026-10-11
- Weakness: CWE-602
Description
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.
Affected products
- Viessmann Vitogate 300: from 1 before 3.0.0.0 — fixed in 3.0.0.0
How to fix
Upgrade to a fixed version: Viessmann Vitogate 300 3.0.0.0. Check the vendor advisory for mitigations.
References
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