# CVE-2025-66263: Unauthenticated Arbitrary File Read via Null Byte Injection

> Unauthenticated attackers can read arbitrary files on DB Electronica Mozart FM Transmitters via null byte injection in the download endpoint.

- **Severity:** High 8.9 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Nov 2025
- **Updated:** 26 Nov 2025
- **Also known as:** GHSA-935j-38v5-5gwh

## What is CVE-2025-66263?

CVE-2025-66263 is a high-severity path traversal vulnerability in DB Electronica Telecomunicazioni S.p.A. Mozart FM Transmitter, published on 26 Nov 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Unauthenticated Arbitrary File Read via Null Byte Injection in DB Electronica Telecomunicazioni S.p.A. Mozart FM Transmitter versions 30, 50, 100, 300, 500, 1000, 2000, 3000, 3500, 6000, 7000 allows an attacker to perform Null byte injection in download_setting.php allows reading arbitrary files.
The `/var/tdf/download_setting.php` endpoint constructs file paths by concatenating user-controlled `$_GET['filename']` with a forced `.tgz` extension. Running on PHP 5.3.2 (pre-5.3.4), the application is vulnerable to null byte injection (%00), allowing attackers to bypass the extension restriction and traverse paths. By requesting `filename=../../../../etc/passwd%00`, the underlying C functions treat the null byte as a string terminator, ignoring the appended `.tgz` and enabling unauthenticated arbitrary file disclosure of any file readable by the web server user.

Weakness: CWE-158 (Improper Neutralization of Null Byte or NUL Character)

## Which versions are affected by CVE-2025-66263?

It affects 22 products.


Products: Dbbroadcast Mozart Dds Next 1000 Firmware, Dbbroadcast Mozart Dds Next 100 Firmware, Dbbroadcast Mozart Dds Next 2000 Firmware, Dbbroadcast Mozart Dds Next 3000 Firmware, Dbbroadcast Mozart Dds Next 300 Firmware, Dbbroadcast Mozart Dds Next 30 Firmware, Dbbroadcast Mozart Dds Next 3500 Firmware, Dbbroadcast Mozart Dds Next 500 Firmware, Dbbroadcast Mozart Dds Next 50 Firmware, Dbbroadcast Mozart Dds Next 6000 Firmware, Dbbroadcast Mozart Dds Next 7000 Firmware, Dbbroadcast Mozart Next 1000 Firmware, Dbbroadcast Mozart Next 100 Firmware, Dbbroadcast Mozart Next 2000 Firmware, Dbbroadcast Mozart Next 3000 Firmware, Dbbroadcast Mozart Next 300 Firmware, Dbbroadcast Mozart Next 30 Firmware, Dbbroadcast Mozart Next 3500 Firmware, Dbbroadcast Mozart Next 500 Firmware, Dbbroadcast Mozart Next 50 Firmware and 2 more.

## How do I fix CVE-2025-66263?

No fix has been published for CVE-2025-66263 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-66263 being exploited?

There is no known exploitation of CVE-2025-66263 in the wild and no public exploit code.

## Other vulnerabilities in DB Electronica Telecomunicazioni S.p.A. Mozart FM Transmitter

- [CVE-2025-66253](https://insights.sbomify.com/CVE-2025-66253/): Unauthenticated OS Command Injection (start_upgrade.php) (critical 9.9)
- [CVE-2025-66255](https://insights.sbomify.com/CVE-2025-66255/): Unauthenticated Arbitrary File Upload (upgrade_contents.php) (critical 9.9)
- [CVE-2025-66256](https://insights.sbomify.com/CVE-2025-66256/): Unauthenticated Arbitrary File Upload (patch_contents.php) (critical 9.9)
- [CVE-2025-66261](https://insights.sbomify.com/CVE-2025-66261/): Unauthenticated OS Command Injection (restore_settings.php) (critical 9.9)
- [CVE-2025-63228](https://insights.sbomify.com/CVE-2025-63228/): File upload in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-66263 and fix it if it is affected.

What it is: CVE-2025-66263 is a high-severity path traversal vulnerability in DB Electronica Telecomunicazioni S.p.A. Mozart FM Transmitter, published on 26 Nov 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-66263 in the wild and no public exploit code.

Affected product: DB Electronica Telecomunicazioni S.p.A. Mozart FM Transmitter. 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-2025-66263/ (Markdown: https://insights.sbomify.com/CVE-2025-66263/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-66263
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-66263
- OSV: https://osv.dev/vulnerability/CVE-2025-66263

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-66263/
Summaries are generated and may contain mistakes; the official description above is the record.