# CVE-2025-9495: Viessmann Vitogate 300 Authentication Bypass

> Attackers can bypass login by modifying HTML elements to access the hidden administration menu and gain full control of the device.

- **Severity:** High 8.7 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Sep 2025
- **Updated:** 23 Sep 2025
- **Also known as:** GHSA-jmw7-g9jf-52hh

## What is CVE-2025-9495?

CVE-2025-9495 is a high-severity authentication bypass vulnerability in Viessmann Vitogate 300, published on 23 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-602 (Client-Side Enforcement of Server-Side Security)

## Which versions are affected by CVE-2025-9495?


## How do I fix CVE-2025-9495?

No fix has been published for CVE-2025-9495 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-9495 being exploited?

There is no known exploitation of CVE-2025-9495 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-9495 and fix it if it is affected.

What it is: CVE-2025-9495 is a high-severity authentication bypass vulnerability in Viessmann Vitogate 300, published on 23 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-9495 in the wild and no public exploit code.

Affected product: Viessmann Vitogate 300. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-9495/ (Markdown: https://insights.sbomify.com/CVE-2025-9495/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-9495
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-9495
- OSV: https://osv.dev/vulnerability/CVE-2025-9495

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-9495/
Summaries are generated and may contain mistakes; the official description above is the record.