CVE-2025-66251: Critical File Deletion in Mozart FM Transmitter

CVE-2025-66251 is a critical (CVSS 9.1) unauthenticated path traversal in the Mozart FM Transmitter web interface. The deletehidden parameter allows deletion of arbitrary .tgz files by anyone who can reach the page. The record names no fix, so isolate the management interface and contact the vendor.

What's affected

• Product: Mozart FM Transmitter from DB Electronica Telecomunicazioni S.p.A. (DB Broadcast), web management interface. The record lists models 30, 50, 100, 300, 500, 1000, 2000, 3000, 3500, 6000 and 7000.
• Component: the deletehidden parameter, which the record says allows path traversal deletion of arbitrary .tgz files.
• Fixed: neither the record nor the researcher write-up we read names a fixed firmware version or a vendor advisory. Contact the vendor for patch status before assuming one exists.
• Severity: the record scores it 9.1 (critical) with the vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H. Both the record and the write-up classify it as serious. The record vector shows no confidentiality impact and high integrity and availability impact, which fits a deletion flaw.

How to check if you're exposed

This is a broadcast appliance, so there is no package manager to query. Work from the device and the network.

1. Build a list of every Mozart unit you run, with its model and the web interface version string. The researcher write-up refers to the web management interface version WEBMOZZI-00287.
2. Find out whether the management web interface of each unit is reachable from the internet, from a partner network or from a flat internal network. Check firewall rules and any remote access gateway.
3. Look at the web server logs on a device you can inspect, or at the logs of any proxy in front of it, for requests to the PHP file named in this CVE from addresses you do not recognize.

If the interface is reachable by people outside the small group that needs it, treat the device as exposed.

What to do now

1. Take the management interface off the internet and off any shared network. Put it behind a VPN or a jump host, with an allow list of administrator addresses.
2. Ask DB Broadcast for the patch status of this CVE and for a firmware version that fixes it. Record the answer with your asset notes.
3. Keep off-device copies of settings and firmware archives, so you can restore a unit if files are removed.
4. Watch the device for unexpected files, new accounts, changed settings or reboots, and keep a known good copy of its configuration to compare against.
5. Add the rest of your internet facing software to an inventory. Safeguard cannot patch a transmitter, but a free in-browser scan at gold.safeguard.sh/scan and a proper asset inventory help you find the other internet facing software you run, and reachability analysis helps you rank what to fix first.

Why it matters

The weakness is CWE-22, path traversal. The page takes a name from the request and uses it to build a path for deletion, without making sure the result stays inside the intended folder. Sequences that climb out of the folder reach files elsewhere.

The record limits this flaw to files with a .tgz extension. That sounds narrow, but on a device where firmware, patch and settings backups are stored as .tgz archives, deleting them can break updates, remove backups or leave the unit unable to restore its settings. For a transmitter, availability is the point: a unit that cannot be restored may mean off air time. The record does not mark this as exploited in the wild and it is not on the CISA KEV list. The advisory trail is thin, since the main public source is a researcher write-up rather than a vendor bulletin, so confirm facts with the vendor. Appliances of this kind sit for years without updates, which is why network isolation is the control you can apply today.

Quick check

Sources

• Researcher write-up: 14 vulnerabilities in the Mozart FM Transmitter web interface
• Safeguard Gold entry

Last reviewed: 18 October 2026.